Alright, anon, time for some fact drops. In the kill-all run, Chara is not the one who kills everyone. You are. The Player is the one who forces Frisk, and Chara, to kill everyone. Sans has never once said the word 'demon'. Not even during his fight. When Chara calls themselves a demon at the end, that's because you turned them into one by killing everybody. And, Chara is not evil. They STOP YOU at the end, and destroy everything, and then you sell your soul to play again. You're the evil one.