Board Thread:General Discussion/@comment-28175157-20160624105722/@comment-27540729-20160624175806

On Nochocolate's tumblr blog, who I think is a very good theorist for Undertale, it has a post where they suggest that the Dreemurr family was being emotionally manipulated and abused by Chara to fulfill their plan. http://nochocolate.tumblr.com/post/142424746470/asriel-how-his-behaviour-points-to-a-case-of

There is also another post where Chara seems to be amused by the suffering of others. http://nochocolate.tumblr.com/post/135990645365/what-was-chara-laughing-at

I agree that Chara is a sicko. While Frisk I blame more for the Genocide Route, Chara still takes some of the blame as they may not have killed everyone, but they definitely would have if necessary. And I bet you they had some influence, or at least killed everyone in the Soulless Pacifist ending.