Board Thread:Questions and Answers/@comment-30546687-20161119211613/@comment-30557719-20161121011725

From what I understand, Chara didn't hate monsters at all. They actually hated humans a lot more that monsters. This is shown by the implied happy relationship between Chara and the Dreemurs, as well as Chara's desire to liberate the monsters from the underground.

I think the game makes Chara seem like a really bad person, way worse than they are. This could be to prove that we, the player, will always blame someone else for our actions. We can't know for sure. Either way, Flowey makes it very clear that we are responsible for what we put the underground through.

Since Chara was essentially awoken by Frisk's determination, they really had no choice but to pretty much go with whatever they did. So yeah, when Chara is suddenly woken up with their last memory being their plan with Asriel failing, they could be traumatized and susceptible to some pretty bad stuff. When Frisk (or more accurately, the player) starts literally murdering everybody, Chara is probably stupidly confused. They then realize that maybe it's not a terrible idea, destroying the world. I mean, it's pretty clear that Chara was suicidal, so ending everything is definitely something they can get on board with.

So I guess what I'm trying to say is that when Chara is saying that everyone needs to die, it's not out of hatred for monsters, but rather being forced into a situation and trying to do the right thing to end all of their suffering.