Victor probably wouldn’t like to admit it but by the end of the novel he shows traits that are similar to the monster. The monster practically brings Victor down to his level after failing at trying to get Victor to understand him. As a result, Victor loses everyone who is close to him and that brings him to the same state of loneliness that the monster has been experiencing ever since he was created. With the murder of Elizabeth, Victor is in a sense dehumanized and develops a need for revenge that was similar to what the monster had previously experienced.
For example, earlier in the novel the monster expresses his emotions after being pushed away from the cottagers and says, “I, like the arch fiend, bore a hell within me” (161). Later on, Victor is talking to Walton and says, “I am chained in an eternal hell” (233). Not only do these quotes sound similar, but they are both allusions from Paradise Lost, which is one of the novels the monster had read. The similarity between Victor and the monster is much greater by the end of the novel.
I think that it’s interesting how in the beginning Victor is so excited about his creation but now he completely rejects the monster. In turn, the creature kills everyone that matters Victor which causes him to become obsessed with revenge and in a way he becomes a monster himself.