While initially cast in a sympathetic light, Asriel admits at the end of the True Pacifist Route that Chara "...wasn't really the greatest person." Asriel states that Chara climbed Mount Ebott for an unhappy reason, and adds that Chara "hated humanity". Chara never told Asriel the reason that they had such hatred. Asriel also mentions that Chara "laughed it off" when the two of them accidentally poisoned Asgore by putting buttercups instead of cups of butter into a butterscotch pie they made for him. I personally don't think Chara is a bad person, but it will depend on the comic.