Somehow this only occurred to me today, but if Stolen Heart doesn’t have a heart, he also shouldn’t have a pulse, or very good circulation if any.
If (being the weird spirit thing he is) he’s somehow able to survive that, he should probably be like getting dizzy or getting headaches at random moments and passing out about half the time. And also oddly cold and dry to the touch.
I am probably going to stick with my initial idea that being a weird spirit thing is largely able to preserve his body, though, so he probably wouldn’t display any obvious blotching or swelling.
Initially I saw him as being somebody who is just able to brave his situation even though it’s very tough, and nobody knows how bad it really is, or would even believe him if he tried to explain. But it seems now like his problems will have to be pretty evident even though he tries extremely hard to hide them, and a lot of the people who work for him will probably have noticed a little slip or two in concealing the fact he’s all but falling apart and be very curious.