The above drawing is not canon to the au--but it is my theory: Avid is trying to intentionally become an animatronic. I didn't understand why he would keep working there if he knew there were killer animatronics around. Unless, of course, he had some kind of motive for needing to be around them. He could be trying to expose them like he tries to expose vampires in canon, but it as far as we've seen, that's not the case (and if it was, it still wouldn't make sense to stick around--he would just quit and try and scream at people that it wasn't safe. no way would he keep putting himself in danger.). No, I think, just like in canon, Avid is really sick. And, same as canon, he is trying to cure himself. Maybe he knew going in that the animatronics had people's souls, or maybe he was just trying to use the ai stuff to his advantage. Either way, as the night guard he gets to learn all the ins and outs of the animatronics and consequently how to make his own. So Avid thinks that if he makes himself an animatronic he can live! he won't die of his terminal illness! yay! (there will definitely be no unforeseen effects and this is not at all a bad idea) I think its kind of neat to think about a person who so desperately doesn't want to die that they seek immortality. its a pursuit that's often born of pride but instead avid wants to live forever because of how afraid he is of dying. its a different sort of vice, but the perceived effects are the same. plus I think it would be really funny if avid used some kind of model adjacent to the count to house his soul; imitation is the highest form of flattery after all
anyway, I don't know much about fnaf (or if my theoretical plan for Avid would even work), but this au is a lot of fun and everyone who contributes are such great artists and I was so excited when I saw they were doing a project together! so even if you don't know about fnaf like me, you can still enjoy this au and I would very much recommend you check it out.