((I had started to work on this but got called away for work ;A; but I'll post it even though you've got this mostly answered.))
Hmmm not sure if this will help you. In the THM questline, the youngest Coco-bro Cocobusi, doesn't really go nuts from aether itself nor from anything his brothers did. He thought that he was weak and useless because he wanted to be a thaumaturge like all of his brothers but he could not because he didn't have the aetheric reserves to do any of the arcane maniuplations that thaumaturgy would require. For him to attempt it would literally cause his death. His obsession with trying to become one leads him to being susceptible to possession by void-sent.
So technically, you don't -need- to know any person that is known as evil. Your character can do this by simply of his own free will. You -could- do it similarly to Cocobusi, that is up to you but it's not necessary.
Hmmm not sure if this will help you. In the THM questline, the youngest Coco-bro Cocobusi, doesn't really go nuts from aether itself nor from anything his brothers did. He thought that he was weak and useless because he wanted to be a thaumaturge like all of his brothers but he could not because he didn't have the aetheric reserves to do any of the arcane maniuplations that thaumaturgy would require. For him to attempt it would literally cause his death. His obsession with trying to become one leads him to being susceptible to possession by void-sent.
So technically, you don't -need- to know any person that is known as evil. Your character can do this by simply of his own free will. You -could- do it similarly to Cocobusi, that is up to you but it's not necessary.