Got a couple of the endings, currently trying to get the rest without relying on the White Room, loved the game. Fio, culinary blunders aside, did nothing to deserve this. 

Given that the main character has presumably been killed by Sofia and replaced by an iteration of himself that is not truly the same individual, I feel that you could say he is now only a figure imitating someone else under false pretenses. An impostor, if you will, and in the ending where he leaves the home in flames or becomes the next unethical researcher, he presumably continues to interact with our human society to survive,  which would therefore make him an impostor among u-*gunshot*