I didn’t think this post was happening, haha, but then, very accidentally, it did.

Swap AU! Asriel lives.

I call this goatswap cause it started with me swapping Asriel and Toriel, before I generally turned it into a “serious underswap” trying to make everything make as much sense as possible.

So ok. I was just thinking about Asriel and what he’d be like grown up (I could be mistaken but I thought a fairly significant amount of time passes between him dying and Frisk turning up) and now I’m just imagining like

He’s like 20 in human years and has some decent sized horns (that I have this cute image of his father compulsively admiring and him being like daaad). It’s almost time for him to be crowned as the heir of the underground.

But when he steps out to give his coronation speech and he announces his plans, it turns out his plans are literally for everybody to stay in the freaking underground forever and never ever hurt humans*. He gets a very mixed response, with a bunch of monsters actually being more or less okay with this but a few of them being kinda outraged and grumbling (see: undyne)

The one that’s the most upset of any of them though is actually Toriel. She’s just totally disappointed that after she tried her very best to be a good mother and raise her son right, after she put up with Asgore for so long hoping Asriel would turn out to be more competent than both of them and this would be better than just taking things into her own hands, he just turned out to be not only as useless as Asgore but worse. She’s too mature to be truly mad at him or blame anyone though (after all what’s done is done and really she can’t blame him for wanting to be peaceful), and just makes the resolution she’s going to strike out of the barrier and get all the souls herself. So Toriel swaps with Asriel.

This is the part where it gets kinda shaky for a bit, haha. In order to start that in the orderly manner I imagine she’d have to somehow have a container safely containing the Chara analogue’s soul. I think I’ll just say… it is Chara, and Chara and Frisk would have swapped but don’t. Just cause in SU swap I probably wouldn’t have swapped Steven if there was another.

I really don’t think Toriel would kill a small human though even if she was task-oriented so I don’t know how Chara died. I’m guessing they like, found out about the soul research department and like a huge dick just went ‘yeah kill me I dare you’, knowing the royal scientist would likely be a huge weenie and after getting past really not wanting to do that, not be able to tell anybody. Which would allow Chara to merge with somebody and do the Asriel thing in lack of things being squared away properly.

The thing is Gaster is still the royal scientist because for some reason the accident didn’t happen. (Maybe Chara shows up to pester him before the time it would have occurred, or maybe it would’ve occurred after Asriel died and Asriel being around kept him in a better state of mind where he was doing more sane things instead of haphazardly improving the core(?).)

Anyway the dickish little kid comes in and annoys him a lot and he’s just like oh my god shut up and let me work geez. He kinda wants to kill the kid out of annoyance but doesn’t at all have the willpower to do it. So……. he ends up resigning. Sans is supposed to be nominated for the position but he’s super not ready for the responsibility, so instead they hire Alphys. Gaster swaps with Alphys.

Of course, now Alphys is getting pestered by the kid that keeps telling her to kill them. She finds this really really disturbing. Probably has a few nightmares about it, geez. Her mental state goes off the edge and eventually, unable to take it any more, she finally gives in. Trembling a lot and feeling terrible, she complies and kills the kid, safely putting their soul in a neat container she hides from everyone. She continues on as normal doing her best to completely hide her totally fractured mental state and what she just did, and does a pretty decent job of deception. (Partly cause nobody ever found out about Chara visiting the lab since Alphys was too cowardly and Gaster too overly calm/easygoing for either to tell anyone)

After a while though, she just can’t go on living, and jumps the heck into the core, assuming that’s what Gaster originally fell into (I personally think it could’ve been because Alphys twice vaguely hints it’s a very weird mutable machine that’s way too advanced for her to understand, and because weird ‘enlightened’ monsters she doesn’t recognise live/work there). Anyway she dies and is scattered across time and space, yada yada.

So yeah. Toriel finds the hidden soul at some point after that. It’s a while after it’s initially caged up, Asriel pretty well by then over the tears he shed when he realised Chara was probably deceased. Toriel is probably hugely distrustful of the royal scientists now (and since Asgore probably still hired them, a bit toward him too).

Toriel: Why didn’t you tell me about this???
Gaster: Would you really have wanted to know? I don’t think so

Years after that, with the caged soul in hand, Toriel marches out the barrier probably during the time most people sleep and without telling anyone; she doesn’t really want to have to face him. She does her best to compromise by trying to humbly ask the humans she meets to sacrifice themselves rather than wilfully murdering anybody, but you can imagine how well that goes. As she actually has an ok amount of power in-game she manages to take out six of the people who are the most unmitigatedly violent toward her, but during that, the many-times-more-adverse-than-called-for response has seriously done a number on both her body and soul.

Nevertheless she upholds her promise to not harm humans more than necessary and goes back. Maybe because of the overwhelming Determination she probably has over Asriel (she has the souls after all) she actually turns into an Amalgamate rather than a flower… I like the idea that she doesn’t even get back into the barrier because she’s too big to go through the hole in ultimate form or something, and in any event is just ominously hovering there when Frisk gets there at the end, waiting to either liberate everybody or fight them to the death if they won’t accept freedom

(Probably her extra matter comes either from the mountain or the vegetation on it or both and she’s just this… well basically if you’ve ever seen Shadow of the Colossus, one of those things. Also because of the thing where boss monsters’ biological age correlates with the state of their soul and they give up soul to their child Toriel would already look a little bit old and when she was in ultimate form man, that little bit of tiredness and weathering would really make her look like some ancient high-fantasy terror)

Ok that gets the really shaky part over with

So. Asgore is still there with Asriel, while Amalgam!Toriel is just kinda chilling out on the peak of the mountain and has probably become an uneasily-told local legend among humans. They’d want to get rid of her except that none of them want to fight her because they can tell they’d get killed yesterday, so they just left her there. For years. I’m almost laughing at that image, her sitting up there ominously at first and years later she’s just kind of sitting up there tired and alone like geez I did not think this through while everyone’s still super afraid of her

Frisk ends up sneaking up there and falling in despite everybody’s warnings to never freaking go to that mountain jeez, because they heard about the terrible monster on the mountain and not knowing about what it’d done were just like ‘oh man it must be lonely’, and then of course they accidentally fall in

I think it would be kinda amusing if the spiders who are always complaining about not having a good place to live took over Toriel’s house and are just like man it sure is nice here after having covered the whole place in cobwebs

I guess that means though Toriel is Asriel Muffet is Toriel? Hawgawd.

Can you fucking imagine. Muffet is like oh hello human yes we will give you a nice place to stay you’re welcome to anything you like… here have a nice spider pie

and then she fucking traps the kid like HELLO NAUGHTY SPIDER SMASHER IT’S ATONEMENT TIME

You don’t really have money at that point either… geez that’s kinda a slight problem. Hmm maybe somebody else rescues Frisk or something. I dunno who it would be. I can’t even think of anybody who dislikes spiders. Hmm uh…. maybe…

I’m still going with Mettaton swapping with Napstablook so that might mean he happens to be floating around in the ruins shamelessly practising some pop song he wrote, and maybe he just freaking floats into the spider house during that not caring and the spiders are like what the fuck we can’t stand this loud annoying singing and just kinda hide and let the kid go

This probably means metta tries to follow them around rambling about himself for a bit

…No but what if like you don’t fight metta when you first see him cause he’s just kinda floating around but then there comes a point later after he’s insisted on following you around and telling you all about himself when you have to step aside and encounter him to get him to stop and leave. If Frisk tries to get him to leave by being nasty he’ll just double down and insist he’s awesome and they’re wrong with an actual air of arrogance he wasn’t showing previously.

If they say like one genuinely positive thing about him he’ll stop though. Because his thing here is he’s actually kind of… narcissistic? Is that the word? (I’ve used that word wrong so many times…) Anyway he’s incredibly ambitious and thinks a *lot* more of himself than he does anyone else but he’s also kinda self-conscious that he thinks it’s impossible to live up to his own super-high estimation of his own potential, and thinks getting famous would be the only way anyone would like him and he could possibly have friends (but that it’s a far-off dream). If anyone shows him love he’ll start behaving a bit better.

While Mettaton is a ghost Napstablook is a soul-bot of course. The thing is though, Metta ended up not becoming a robot because, with his even more inflated ego in this au, he’s convinced that it would absolutely never work because no corporeal form could possibly contain all the awesomeness that Mettaton is supposed to be, and then of course it would be a huge failure and nobody would like him so bad so sad big tragedy and he just doesn’t want to risk that. Note that he’s still called Mettaton and it’s because he couldn’t not just start going by his dream stage name anyway even though he knew it was never gonna happen

Napstablook became a robot because it broke their heart seeing their cousin so extremely ambitious but also completely unconfident in his abilities and thought, well maybe if I can become a robot and do a few small shows, my cousin will see that if he just gives things a try and has some faith in himself it’s not gonna be that bad. As for doing a couple small shows… that’s a work in progress. They’re still pretty darn quiet and low-energy, although their solid body has given them a hair more confidence at generally requesting things of people.

(Initially Mettaton, doing the mettaton thing, just freaking dropped into Gaster’s place one day like ‘hey’ and Gaster cause he kind of has a slight character flaw of liking to mess with people even as his normal alive self, just found his sudden entrance amusing and was like heh I like you. He wanted to build a body for mtt cause he was certain they’d be great friends but mtt refused and when his cousin found out they asked to be embodied instead and got their wish)

Can you imagine a tutorial from Mettaton

MTT: So there are a few spikes here. Just press space to float, darling, I know you can do it
MTT: *cruises right through the spikes*
Frisk: …………………
MTT: Well that’s a shame. *continues out of the room*

The interesting thing about Gaster is I feel like Alphys’ basement lab probably originally belonged to him in canon, judging from how old it appears to be; it has the ‘dt machine’ which he may have designed, and generally looks like it’s not as clean as it used to be years ago. So (if that was true I mean), it would kinda be the most natural thing for him to have cleaned out her place and moved in there after the ‘accident’. (Even knowing it was kind of in bad taste to do so, cause nothing fazes him. He’s Gaster, the most unsettling dude around; he’s not afraid of getting haunted or any stupid crap like that. Ghosts are his best friends :p)

Undyne kinda didn’t get the same chance to get close to Dr. Alphys as she would have otherwise (I think they still interacted before she got her position but after that happened she was really preoccupied so it kinda stopped there). That could mean she’s less gentle and more of a jerk, but then again she has not one but two big fluffy royal goats to protect so… I dunno. She grumbled when the plan of inaction was announced but didn’t flat out burst into rage, cause overall, it’s hard to hate Asriel, heck maybe he even did something cool versus her once and she actually admires him. She’s probably pretty pumped for the queen to return though if she has any idea that Toriel going and getting the souls was a thing, cause she still has dreams of leading the second great war. (She can dream anyway.)

I like the idea of Papyrus swapping with Undyne but I’m not sure how it would work??

Hmm uh….

Ok, one thing I could kinda see is if Alphys becomes the Gaster that like, Undyne keeps detecting traces of her everywhere and is like really really wondering what happened (because nobody got the full story on that and Toriel is the only one who even knows that Alphys was definitely connected to Chara’s death/vice versa) and sorta, falls in love that way. This leads her to travel around a bit more in search of the mysterious figure, and experiment with more things. She’s still not particularly good in a lot of environments (geez can you imagine how it must have been for her before the monsters found waterfall? if she wasn’t born there that is) so she often wears a big camel hair coat for insulation.

Her getup and main obsession have kind of earned her the reputation of ‘Inspector Undyne’. She’ll fight anybody who calls her that, but… all her investigating has kinda made her good at puzzles. She’s found she’s particularly good at navigating networks of traps, as well as designing them to be navigable by pretty much nobody else.

Papyrus, who lives in Snowdin, has always dreamed of capturing a human. He’s been training like crazy for the day, both knowing humans are way stronger than monsters and that if he doesn’t train himself to kill, he’s probably gonna end up doing something embarrassing like offering to let it stay with him. He knows about “inspector” Undyne and thinks she’s kinda cool, but realises that only tough people like her can afford to play around with puzzles like it’s nothing. Nevertheless he’s doing his best to try creating a bone trap technique that’s as good as her spear trap technique.

He did get the memo that the new king wants nobody killed. It’s kind of a disappointment for him really, cause he’s so close to getting over his reservations about taking a human soul. With “inspector” Undyne so busy with her investigation, she didn’t have the time to put into the Royal Guard, so Papyrus worked his way up there instead. He did it mostly through asking nicely and charm and stuff though, so he considers himself a serious impostor. He’s really afraid of being fired, and wants to do his best to make the king(s?) proud (to make everyone proud, really), but now that his plan of taking that soul and bringing it in to prove himself is kinda shot he really doesn’t know what to do, and has just been continuing his training exactly the same way in lack of any better plan.

When the human arrives the main thing Papyrus does—cause he’s totally confused about whether he should be violent or not—is make a really really grand entrance and monologue a lot to bluff. He does a lot of things to try to actively trap the human so he won’t have to face them head-on but of course those don’t quite work and eventually the kid gets there. Papyrus is just like aw shoot *now* what do I do, but finally decides to just fight as hard and as grandly as he possibly can, cause surely, that’ll prove he’s worthy of his job. In order to spare him Frisk would have to like play along and deliberately block attacks that weren’t super hard to evade and otherwise contribute to the fight being dramatic. (Kinda like mtt’s ratings thing mechanically.)

After that, Papyrus can trot out a really solid excuse of ‘I did my absolute best but they refused to die’.

Before Frisk runs into “inspector” Undyne they stumble across a handful of trap puzzles she’d been experimenting with, after which they find her somewhere nearish engrossed with the latest Alphys-related clue. Though her core tendency would be to kill humans, I kinda think that like, maybe if Frisk just didn’t even say anything but just joined in with some suggestions as she was muttering to herself she might not notice. And just be like ‘hmm yeah you might be on to something… that’s a good idea…’ etc. without even bothering to look back and realise there’s somebody unfamiliar there, much less a human

When she finally looks back for a completely different reason and sees that’s a human she’s pretty shocked and probably has a lot of conflicting emotions. She knows that a human dying had something to do with Dr. Alphys dying so that gives her a first knee-jerk negative reaction to humans. She’s really wanted the leadership to mobilise all the battle-ready monsters to fight them, and maybe to be part of it, until she started her investigation. But at the same time, she’s kind of impressed anyone could get through her traps, which are notably better than Papyrus’ attempt at similar. And kinda realises in that moment that if she’d been able to fight humans in the war they might have been unimaginably tough. Eventually, all her rapid deductions lead her to the conclusion the human is probably dangerous and she probably needs to get rid of it.

(Also cause she lives by her own rules and even if Asriel doesn’t want that soul he is going to get it and he is going to like it and he is gonna become a proper leader by god)

Her attacks against Frisk would probably be pretty cool honestly, just this variety of weird and frightening traps you have to dodge skilfully. (Keep in mind that Papyrus already made you do the blocking thing so Undyne gets the endurance dodging thing.) To spare her you’d probably have to… I don’t know. Convince her humans aren’t dangerous somehow?? That sounds hard, haha. Maybe like, she starts muttering about clues again in the middle of the fight as she lets the traps do their thing and if Frisk gives her the right answer to whatever was the big question she was trying to solve today when she finally just plainly says it to herself cause she’s stumped (it’d probably be free response so you couldn’t lower the stakes by trial-and-erroring it; risk of failure is an important part of her fight), she goes back into ‘human? what human?’ mode and just kinda forgets she was trying to destroy them until a little later when she suddenly realises and is like goddammit did I really do that. Ah well you really want to help me don’t you, maybe you’re not that bad.

Frisk shortly finds out that Undyne was spying on Gaster a lot cause he’s such a cryptic dude and would always give her amusing non-answers when she tried to ask direct questions. She of course wasn’t really able to find out much, other than a shitton of little quirks he had and the fact he apparently hung out with ghosts a bunch.

Undyne is also still friends with Papyrus. Because of his position she’d visit him to see if she could glean any rumours about a monster revolution coming up, which of course there never were. But he was still cool to visit.

(tbh her not-infrequent asking about that and the way being Undyne, she would probably remark more about his power than his personality despite finding the latter pretty cool too, might be a good part of why this version of Papyrus thinks he has to be violent to gain approval. The most interesting person he knows seems to think war is an inevitability, so clearly, everybody probably wants that and if he really wants to be popular and admired he needs to be their hero.)

When Frisk gets to Gaster the first thing that probably happens is he takes one look at them from a camera or something and just thinks to himself ‘aw man, not AGAIN’.

(I’d like to think that like, Gaster just has cameras everywhere cause he likes to snoop on people, and it has nothing to do with TV. When Undyne finds out that while she was spying on him he was also spying on her she gets so completely embarrassed, while Gaster is just like ‘don’t sweat it, I love it when people try to spy on me. It’s a riot’. It’s like, you just can’t get ahead of Gaster, he’s always one step ahead of you, but at least he’ll take in stride whatever you tried to pull on him. Particularly if you’re trying to find out his secrets you just will not succeed.)

So Gaster sights a suspiciously Chara-looking kid. Just to kinda test the waters he brings out Napstablook. Napstablook doesn’t attack but if Frisk wants to be mean they can unknowingly mock this with something like ‘are you going to kill me or not’… which if they do that will cause Gaster to unexpectedly leap out of the shadows and try to destroy them. He has his own Gaster Blaster or ‘Aster moves’ or whatever he’d have, I don’t really know to be honest. I’ll continue to headcanon Gaster just has a distinct fighting style of ‘Aster moves’ and other people like Sans can also become able to use their own ‘Aster moves’ if they get to know him well.

God. Can you imagine if he had like four different special attacks that were all Aster puns like

* Gaster is readying Raster Caster
* Gaster is upping the pace. Next up: Caster Faster
* Gaster is done playing around. Next up: Disaster Vaster
* Gaster stands ominously still. Next up: ☝✌💧❄☜☼ 👌☹✌💧❄☜☼

Maybe just to invert the first mtt ‘fight’ you’re actually asking Napstablook a bunch of questions and by like the third round of them that rude one is just kinda in there. …Heck, maybe Undyne actually asked you to interrogate them for her because nobody knows you so you can get away with more than any local could

I don’t think Napstablook would know any of the answers to her questions though, haha.

Maybe you could also find a question in there like “are you ok?” which would get a response like ‘yeah, I guess. …uh, thanks’ and get a favourable response from Gaster who realises you’re not up to any messed-up plans today.

Unlike the other boss monsters Gaster actually takes Asriel’s orders not to kill anyone pretty seriously; so as long as Frisk isn’t causing trouble his first inclination is to trust them and be like yeah our king’s orders were not to kill anyone. Didn’t anybody tell you that? I can’t believe people these days

He probably knows a number of relevant things, for one he probably knows about Toriel running off, due to his freaking cameras. And of course he knows about Chara and the fate of Alphys, though he wouldn’t bring that up yet since nobody really needs to know.

So Gaster’s pretty nice mostly. But I think that the instant Frisk tried to go into the core he’d be like oh no you don’t. I can just imagine like, behind the scenes he’s just watching them go up to the core on his cameras and tensing up with every step they take like don’t do it. Don’t do it. *Frisk walks straight on into the core door* oh my god. Then when they’re in there he just Sans-slides into the room by teleportation with his arms out to either side and gives them a lecture

He wanted them to take another route instead (note how in canon Alphys claims that the core elevator is a shortcut in addition to another longer route) but for whatever reason, Frisk can’t go the longer way so with no other option, they end up going to the one place Gaster specifically told them not to go and that it would be too dangerous to go to.

(The thing is, he built the place, so he’d be the one to know exactly how dangerous it is. If foolhardy young monsters want to come play in it and ignore his warnings, he’s like, well ok, I’m not going to stop you, but knowing humans are somewhat important to Asriel, he’d rather not risk anything happening to this kid. I like to think the reason that in canon Alphys thought going into the core would be a perfectly fine and dandy plan and clearly perfectly safe is simply that she has no idea how it works and tends to make pretty big miscalculations sometimes.)

So, instead of mtt/Napstablook Frisk just fights Gaster. The Gaster fight if they mess up versus Napstablook is probably impossible to win by sparing him, so it would be the first fight against him either way. (Though, that certainly doesn’t rule out him remembering it like Sans and hoping it was just a fluke…)

Sparing Gaster… hrm. uh… well. Alphys helps you in the mtt fights so maybe Napstablook could help you in the Gaster fight?

Just imagine though

You have to wait for Napstablook to take like fifteen turns to say one sentence

‘I’ *turn*
‘I, uh’ *turn*
‘um…’ *turn*
‘excuse me-‘ *turn*
‘sorry to bother you but’ *turn*
‘…I’ *turn*
‘I think’ *turn*
‘you’ *turn*
‘I think’ *turn*
‘I think that’ *turn*
‘I think you should let the human through’
*gaster just looks at them surprised instead of attacking*

I guess that was only eleven. Anyway, with that Napstablook has kinda given an unusual show of confidence; with the stuttering aside, they just stood up to one of the most ominous (and possibly most powerful) monsters ever. Gaster is kinda touched by this moment of personal growth and is like ok. but be careful.

When Frisk gets to Asriel and Asgore they’re both pretty happy to see them. Heck the similarity probably has Asriel crying a bit. He’s so ready to just welcome in his new little “sibling” he can’t contain it. Frisk is going to be so happy with their two wonderful goat dads

But then there’s the whole souls thing.

The fact that Frisk would need a monster soul to get out of the barrier, but also

The thing where the former queen ran off with Chara’s soul and they suspect she may have gotten all the souls they need to break the barrier but they don’t know and are kind of worried. On one hand she could have died, which would be fairly bad. On the other, monsters can absorb souls and well… insert exactly what actually happened.

I think they’d be kinda dismayed to learn that all the boss monsters tried to kill you for various reasons against their wishes, haha. (Though I can only imagine Asriel bracketing relief that they’re okay with a quiet ‘though gaster creeps me out geez’ :p)

Anyway. Asriel re-announces his pledge of nonviolence (maybe because he hopes the boss monsters will listen to him this time :p) and for everyone to stay in the underground. Maybe he apologises for the ambiguity that occurred after Chara died, but more importantly, owns up to the fact that a handful of monsters really wanted to go free, so he’s really sorry about the inconvenience; he loves everybody and isn’t doing this because he thinks their dreams of freedom aren’t valid, but because he thinks there must somehow be a better, more mature solution than mindlessly killing people.

This new speech is pretty well received… by everyone except Toriel.

Somehow, she happens to start listening in on this, and decides to amalgam-melty-thing the heck through the barrier just to tell everyone they are wrong and they must stop listening to Asriel because she’s now many times more powerful than all of them put together and there’s literally nothing stopping them from victory over the barrier and humans now except them all being pitiful cowards.

(Asriel: I disagree
Toriel: *opens up her giant mouth and blows out a huge firestorm that instantly incinerates him*)

(…I’m not sure if I actually like that for perfectly mirroring Flowey’s bullshit or it’s just too excessive.)

So yeah, basically ultimate!Toriel is ready to fight literally everybody (literally) for the right to lead them in the war, until they all surrender. No matter that that’s completely losing the plot on her part since becoming a terrible military dictator is basically the exact opposite of leading them to freedom.

I think she actually wouldn’t know what to do when Frisk appeared to her.

First she’d see them and think of the time she was frustrated that Chara died so she shouldn’t hurt them. But she’d realise they’re the most peaceful of the lot and pretty much the figurehead of this whole inaction movement now and by golly if you’re neutral in a time of oppression you might as well be supporting the oppressor. But then… didn’t she do this whole thing out of a desire for Asriel to become better? And now she’s just killed him to prove a point? What’s she even fighting for? …Right. Freedom. Justice. Restoring order. Saving every one of these idiots who doesn’t know better. It’s for their own good she wants to bust them all out and lead them to victory, and they’ll like it, the ungrateful rats. That’s the only correct option.

Eventually of course Frisk can beat her. This would have a different dynamic than the battle against Flowey when ultimate!Toriel specifically wants to subdue all the monsters rather than absorb them; the boss monsters and a few other audacious monsters might actually be able to pull combo techniques with Frisk, who wouldn’t usually so much have their own attack to use but when monsters channel their powers through them can sorta use bullet patterns like a monster. (ok I just think combo and fusion moves are cool, you got me :p)

After that…

The souls probably escape while leaving the barrier as it is considering that’s what everybody just fought for. Toriel’s…. she sorta has faint scraps of one cause she never quite died and just got torn apart by her surge of power first. I guess that one stays?

Toriel goes “back to normal” but at this point, she doesn’t really have a normal. The closest she can get to normal is her original size, but with a bunch of random grass and flowers and rock ridges and stuff embedded in her body. (It’d actually be sort of pretty and aesthetically pleasing in a weird way, especially for an amalgamate.) She is just like, really really broken. She did a bunch of bad things, but most of all, after firmly deciding never to harm children ever, she tried to kill one in basically the most overkill way possible. And of course, killed her own son. This is her one most sacred principle, to not let terrible things happen to any child, and she violated it pretty much as soundly as she could.

Asgore because he’s a butt and never learns anything still likes her enough to keep trying to calm and reassure her. It’s still the case here they aren’t a couple, but he cares about her as a friend, and feels like even if she might have technically deserved to be obliterated (impossible as that would be) she doesn’t deserve to suffer like this, completely unable to forgive herself, but unable to die, and with enough soul to cry but not to regenerate a whole one. (If she really is full of Determination, that could be why. She could never get her soul-to-determination ratio high enough to feel normal)


I’m divided on whether this is decent or conflating the neutral and true endings too much. When I actually looked it up (they were very muddled in my head before I did that honestly), it seems like I got it right that “ultimate” flowey happens on neutral and makes use of the souls there, so ultimate!Toriel there is pretty ok, even the part with her tackily burning asriel. The part of it that was based on conflating things is the combo attack part cause that was sorta based on the lost soul thing, but I don’t really want to change that because it fits thematically.)

Now, there’d still be a true ending where Asriel would be intact and the barrier would be opened and even Toriel might have a slightly happier ending. Somehow Gaster would play a role in figuring out how they could make all this happen.

Of course, in order to explain exactly what his plans are, he has to reveal his secrets. …Gaster. Reveal his secrets. Yup.

I’ve theorised what Gaster was doing in canon, besides working on the core, was working on some kind of way to mess with SAVEs, given you have to make a minor edit to your save files to get access to the “gaster followers” that tell his story, and to the “mysteryman” room which would appear to be him. Sans appears to have some association with him, and possibly to be able to teleport and remember a few things regardless of restarts and resets because he had something to do with this research.

Now, this is a much much shakier spur-of-the-moment theory, but, I’m kinda guessing that maybe with the “unfamiliar people” in the photograph in Sans’ secret room, semi-assuming they’re the memoryhead people… something un-Gaster-related may have happened to them, and Gaster may have tried to resurrect them, only to accidentally erase them from history instead. Or alternatively, maybe something would have happened to all of them but he actually managed to save Papyrus and Sans.

Either way, maybe he has the power to save people when it would otherwise be completely impossible?

Having few details about Gaster I’d feel silly trying to make too much stuff up here. But I dunno, I think by revealing where he screwed up with things and what the hell he was doing in the first place, with a little help, he could figure out a way to ensure Asriel was safe and things turned out right.

Honestly I think Gaster could have a pretty cool little storyline where for whatever reason they have to like fix up a handful of seemingly unrelated broken fragments of things that happened to return them to the timeline and it turns out actually one of these things was very related and the others, well they were kinda necessary in the big picture even though individually they seem like they could have been left out.

Possibly, Gaster may have had the ability to break parts of history, preventing them from happening, and have intentionally broken the things he is now fixing. It’s an idea that’s kind of out on a limb as we really don’t know Gaster has that much power; the thing that gives me that idea is that there are two secret scrapped rooms (maybe three) where Gaster has left the message “* REDACTED” as if maaaaybe storywise he had some part in the redaction, maaaybe he removed these rooms from reality for a reason. This is really not my serious theory for Undertale but I need something for here lol :p

Just letting this stuff stand, I could see like, there was a vignette where Asriel visited Gaster’s lab but Gaster broke it because overall there was way more risk this would result in harm to Asriel than anything good would come out of it. (Maybe cause he would’ve ended up there after Chara and Alphys die and had to deal with that? Gaster has a compassionate side here, for once this might be something he doesn’t have the will to hide…) But when he unbreaks it it opens up the possibility for him to work with Asriel and give him the semi-invincibility* he and Sans have

So that like, when ultimate Toriel barges in and tries to incinerate Asriel

Asriel seems to be destroyed…. but then he just freaking Sans-slides back in right on top of his own ashes

For comic effect Toriel might try it like two more times just because she can’t believe this just happened, but of course, it fails, and it fails again. Asriel just continues to stand there, refusing to resist her or lead the other monsters against her, and she gets very confused.

Asriel finally explains to her that nobody’s siding with him because they think her desire to do them good isn’t valid, and nobody wants to stomp on her dreams of freeing everyone. It isn’t his desire to stomp on people’s hopes and dreams, just to find a better way to achieve them that won’t be destructive and awful. Jeez, was she even listening to what he just said?? He loves everyone. He wants to save everyone. Including her, and that’s why he won’t fight her. Mom. Do the right thing. Give everyone actual freedom. I want us to all be free but they’ll never listen to you if you make freedom sound like the worst thing that could ever happen to us. Don’t do nothing to help your people. Don’t disappoint me.

I think that the incredible amount of growth Asriel is demonstrating might actually cause the remainder of her soul to drain out.

But then again, if Asriel has been messed up by Gaster, his soul might not work quite normally. idk. If we’re talking about “negative photon readings”… but something is supposed to be taking away light… maybe he might end up giving her soul instead of draining it like he was supposed to??

Then Asriel would get older and look like 30 in human years or something. But his really weird mountain-looking mom would be more or less normal. Except for the part where she looks like a small mountain, her soul is still a teeny bit shaky, and she still feels a little weird about everything that just happened. And is very wary the humans will probably want to kill her. It might be impossible in this state, but that wouldn’t stop the attempt from being an unpleasant experience she’d rather avoid.

I’d be kinda worried for the monsters more than in canon because of the whole ultimate Toriel incident, which would do a LOT more to convince humans monsters were bad than the Asriel thing… but I dunno. I think this version of Asriel would really have their backs. I think if the humans could meet Asriel, maybe they could ease into an unsteady peace with the monsters.

So that’d be the true end.

Now, some loose ends/things I didn’t get to address yet.

Loose ends

There’s been a distinct lack of Sans in this post. You could say it’s been a bit—oh dear here it comes—sans Sans.

Part of why is it’s hard to think of a good role swap for Sans when he doesn’t so much have a good contrast. There’s Papyrus, but if you pay any attention to Sans’ story they’re pretty unrelated lore-wise—Sans has Seen Some Stuff, which Papyrus seems to have been completely unaffiliated with. Gaster is already doing a bunch of Sans things here right down to a teeny bit of wordplay, but all that was supposed to be a wild guess based on canon more than a swap thing.

It’s not really as “deep” a swap as the rest of them but idk maybe Sans could swap with Asgore. Cause what does Sans do? Nothing. And what does Asgore do? Nothing. :p …Yeah, that was a joke, but only halfway a joke.

Asriel is king though… Maybe Asgore has decided he’s old enough to look after himself so he can afford to make some rounds to see how everyone’s doing or something.

Oh man. Imagine Asgore just like. Seeing the human having killed one of the boss monsters but because he’s too much of a wuss to do anything just being like ‘please be careful with my people’ with a tired expression instead, and that’s his bad time warning

Yeah he’s just kind of visiting each of the places as the kid gets there and idk, he doesn’t really do the Sans shifty thing so it would have to be more coincidence that he happened to be at the same leg of his leisurely walk back to the capital as the kid was, but… he’s just kinda there commenting on the ‘weather’ (inasmuch as a cavern has weather) and stuff

It also makes a surprising amount of sense for him to just want a little time aside with the kid toward the end to talk about random things and sorta try to persuade them to stay, because his son Asriel would be so happy to welcome them in. How like, he tries his best to look out for everyone but especially small humans, and if they’re ever in trouble… well… um…… yeah, he hopes they’ll never be in trouble. But um they haven’t been in trouble yet have they?? No! …Right? Everything is going to be great.

Sans as Asgore doesn’t work quite as well but at least it makes sense. The thing about Asgore is that for most of the game he’s just talked about in a weirdly ominous way but always with the incredible-sounding parenthesis of “he’s a really nice guy!”. And like, I dunno, I could kind of see people talking about ‘we wouldn’t have this problem if Sans was here’ ‘Sans? Oh, he could be here in a second. Heck, he might already be watching…’ ‘Nobody wrongs Sans and lives… he’s too nice a guy for anybody to ever think of wronging’ and other things that kinda suggest Sans might be some kind of elite and effective figure you want to be careful around. He’s anything but, of course. People only talk about him as if he’s a legend because he’s too lazy to be there.

…This would suggest Mettaton specifically tells you to watch out for Sans though and…??
That’s. A bit inexplicable.

Unless… like, there was one time when Sans very accidentally said something that brought out his insecurities, only meaning it as a joke.

Sans: but hey, at least I don’t plaster my face everywhere and go “look at me i’m the epitome of style”.
MTT: .__.
Sans: …you ok, buddy?
MTT: *silently drifts away*
Sans: uh. was it something i said?

MTT to Frisk: Keep clear of Sans. He’ll destroy you.

I don’t know exactly what Sans is so busy doing. Maybe watering flowers? :p Maybe like, he took up a job maintaining various parts of the castle just so he’d have an excuse for being too busy to take much part in Gaster’s stuff and also wouldn’t have to be a sentry where he wouldn’t do his job anyway. But I think he would still just sleep a lot of the time so he’d never run into the problem of not having work to procrastinate on and not be able to point to that whenever anyone tells him to do something he doesn’t want to.

When Frisk ran into Sans he would like, be this dramatic shadow in the doorway as if he’s going to stop you from getting to the king with his legendary sans powers but then he’s just like ‘hi’ and gonna show them around and stuff.

I wanted to get Tem into this somewhere and also the lizard kid but I had no idea what to do with them. I couldn’t think of a swap for the lizard kid, and. I considered Tem being Muffet and the spiders wanting money for college… a million teeny spiders wanting to go to college made me laugh so much (you have no idea) but ‘tem flakes, made with real tem!’ was just way too disturbing, no thanks. I’m sticking with the spider pie thing.

There are many minor characters I could maybe have looked at but this post is already 9000 words long and that’s pretty darn long when I meant it to be maybe like 2000. So yeah.

Genocide scenario

Well, I kinda already covered Gaster in this a little so first, him. In neutral/good he’d ambush the kid at full force if they showed signs of being like Chara. In genocide? He’s always watching via his cameras so pretty much, he’s just gonna do the same but do it the moment they get there. While he’d get ample chance to show he was cool and not that bad to pacifist!Frisk, here his encounter would purposefully be the literal most mysterious and concise way you could introduce a character in an undertale-style battle: pretty much zero explanation of what’s going on at all, you just suddenly have to fight this really creepy and powerful dude that just kind of suddenly jumped in and it’s like whoa. I also think he’d say everything in Wingdings except the one or two things he’d already say in Wingdings (gaster blaster?), which he’d make readable so there’s still the ‘oshit this… is probably important and bad’ factor.


neutral!Frisk: *kills Gaster*
Napstablook: oh………………

So… mtt and Muffet. The thing with them is I established mtt rescues the kid from Muffet so mtt would have to be distracted somehow to allow killing her. Probably like, it’s necessary to deliberately listen to his “tutorial” for him to interfere, and if just ignored, he won’t.

While it would be funny to imagine ghost metta not really realising people are dead cause he was so preoccupied with himself, that’s not very interesting or giving him enough credit and it would be funnier if he actually cared and took it way too personally.

Like, he’s just like, ‘aw man, there’s nobody here now. …Is it because everyone hates me? Did they all leave because they hate my guts?’ (what did I dooo)
Also if he found Napstablook destroyed…

MTT: No. It can’t— No. Aaaaaa…
MTT: I always knew this was a bad idea. I’m going to stay like this forever.

I don’t see him crying really at all otherwise but I think either of those things would do it. I see him as, while only showing it a little, appreciating Napstablook’s support a lot and secretly really counting on them to succeed. He pretends he ‘really doesn’t know about this’ but actually, it means a lot to him they’d do that and it’s starting to inspire hope in him. When he finds his cousin destroyed it’s just like. The biggest downer.

Papyrus… actually I feel like he’d be strangely okay with dying. I mean, the way that a lot of American war veteran charity commercials imply that you’re a “true hero” if you got injured in war (I hate that by the way) he might be convinced that dying for his people has finally proved his bravery and willingness to hold nothing back. He’d be kind of relieved to see his opponent actually being serious because he can actually use his full power and not worry about killing the kid.

Undyne… man. What if Undyne heard about the disappearances and switched her investigation to that. And then she steps in and finds the killer and is like you can’t hide any longer. I know it was you. (Admittedly that’s less cool when I realise that basically puts her straight back to canon but, whatever.)

In genocide she actually decides to own the title of “Inspector Undyne” as if that’s just who she is, because apparently an “inspector” is exactly what this world needs, and if that’s the case, that’s what she’ll be.

Of course if Papyrus dies (neutral probably) Undyne’s going to have to realise that she contributed to it. She’s gonna have to have this moment of ‘man… I didn’t think he’d take that war stuff to heart so much’ where she starts to feel bad that her… priorities? caused somebody cool to die for not much good reason.

I…. have not finished the genocide path in the game. So I can’t really say anything about Sans or Asgore. All I know is a shred about Sans and how nasty his fight is

Hmm uh… one thing that strikes me is that Asgore and Asriel are both there in the pacifist scenario. So maybe the thing is, Asgore is surprisingly nowhere to be seen until the killer steps in to face Asriel, but just as they’re standing eye to eye and the fight is beginning, Asgore steps in with his trident thrust into the ground and fights them instead. Because Asriel is literally right there and in immediate danger Asgore becomes more powerful to protect him. There are hints he was kind of formidable in the war so like, this would be him going back into that mode I guess

Yeeah that’s a bit shaky cause I’m not even sure where Sans fits into it

It’s semi-straightforward what happens when they get to Asriel though. Asgore dies, they walk up to him… Asriel just kind of looks at them and just says something like

You’re here.

Man, it’s hard to imply what you want to imply in any single line of dialogue…
It’s supposed to be like, he’s recognising that yep, there are terrible people in this world and they are right here right now. That hypothetical awful party showing up solely to wreck his dreams that he believed with all his spirit would never appear because the world couldn’t possibly be that bad? They’re here. It’s over.

Toriel for whatever reason amalgamifies in to see what the hell is going on, I guess because there was a lot of noise in there just now, and gets to see the kid dispatch Asriel right in front of her.

Though she normally would have killed Asriel herself, seeing this kid do it (and somehow being able to tell just from how empty the place feels that they got everyone else too, I mean monsters can feel others’ souls “beating” sometimes) makes her feel decidedly differently. She actually realises it’s something she didn’t want, and that really she wanted to protect the monsters from this. And now they’re dead.

Toriel just kind of withdraws her body back out of the barrier to be ultimate and lonely all by herself on the mountain, given she wouldn’t really gain anything by fighting the kid. They probably try to stab her a bunch but it’s useless, not only is she invincible but it’s not possible to hurt her anywhere near as much as the realisation of what just happened did, so she can hardly feel it. I dunno how that even ends. The kid just starts walking back toward humans and she just kind of peers down over this wistfully?

kind of a really blah ending… but then again at least it isn’t mountains upon mountains of Flowey-brand bullshit like I’m positive the actual one must be

I almost don’t know why I even typed this section tbh


Toriel = Asriel/Flowey
Muffet = Toriel
Asriel = himself mostly, though he gets a couple Asgore things
Alphys = Gaster; Gaster = Alphys
Undyne = Papyrus; Papyrus = Undyne
Napstablook = Mettaton
Mettaton = Napstablook, tutorial
Asgore = Sans; Sans = Asgore
Chara & Frisk = same?

  1. This is just a brainstorm/outline and not any kind of finished “story” obviously
  2. There is probably a ton of stuff in here that doesn’t quite work but… eh. I tried. I really did.