Maybe?

Imma make a guess
I feel like vasya gonna have a split personality where vasily the 18 y/o him would comeback again sometimes soon and they would go back and forth between vasya and vasily everytime there's a trigger (just like DID)

I mean the only thing i know about how someone develop a DID is through childhood trauma but....
this is fiction right? ╮(￣▽￣)╭
I watch dissociaDID too much lmao