Here’s another Stablehand post I have G.E.M. to thank for. Note: if this sounds like guidebook material it’s cause it kind of is. Probably this’ll be rewritten and put in the guidebook in some form later.
So… Eterea have this thing called sustanszia (“substance”). Literally, it’s how much aethereal matter is in them. Practically, it acts like kind of a combined HP gauge and power level.
First of all, Eterea need a small amount of it to exist. If it runs out, they basically die.
MBs are made of a few different parts. Sustantia, which is either Directed or Undirected, essentia, which is typically one or more attributes and possibly one or more attunes, and agency.
Sustantia comes from Totalia/Nanta. Essentia is something that is constructed as an MB “grows” and finds its own personality. I don’t know where it comes from.
When an MB becomes a locale (a very Thematic form), it becomes less conscious, but not because its consciousness is lost, simply because its consciousness was made of a number of parts working together that are now functioning independently.