@Rvan group
Yeah, sorry my explanation was a bit confusing lol
Demons turn into demons when their bargain is fully complete (i. e. When Rvan is under full control of the Demon King (that's a whole other story, but basically the king of the demon race as the name implies))
Rvan can successfully commit suicide, but not die from that (sorry I'm wording this really weirdly). Like if the demon bargain hadn't happened, Rvan would be dead from suicide, something that couldn't have been saved. Of course, the demons also kind of pushed him away from successful suicide, but things that could be considered a mere coincidence, like “oh, no, Erik's football game was canceled, guess we have to go home early… Rvan, what are you doing!?!", whereas the car crash where there wasn't a way to push him away from death that time (again, I'm sorry that's worded super confusing, I totally get it if I made no sense at all lol)
For Erik sellling Rvan's soul instead of his own is actually because, since the bargain is working to keep Rvan alive, of just the way bargains work if that makes sense. It works that way so people can't just offer sacrifices for immortality or something in the demon world, they actually have to give something up of their own. Erik is kind of a special case, the only way Erik could set up the bargain was because they were close blood relatives (like sibling, parents, children). Erik was more of a vessel for the trade to happen. Erik technically doesn't get anything out of it on paper (he does get to cherish his brother for longer tho) rather, Rvan keeps his life. It's a pretty crappy deal from Rvan's perspective because he doesn’t want to live, so it seems like a bad deal in general.
In any other situation it would seem like a way better deal, let's say Rvan was actually dying of cancer (<— Just to be clear, that's a made up scenario) Rvan would get something out of the deal, i.e. Rvan being cured, but he'd have to give up his soul.
The deal is crappy time-wise because the demons generally always get what they want lol, it's really all Erik could bargain for. The demons wouldn’t give up any extra time over one year. Demons who make deals with humans are taught to always get the better end of the deal, so they aren't very generous in certain aspects.
Yeah, some demons do kind of look creepy and just seem off even when they are human-like, for instance, some wear old fashioned clothing and don't really fit in with the modern era, some don't talk very much or just talk in riddles, some just kinda stare blankly at things/people. Maybe should I have the protagonist start noticing more of these “people" around where he lives?