after a True Pacifist Route, you decide to go back into the Underground to save those you couldn't. It was Chara's turn, who you encounter in Last Corridor. You are aware that Chara wishes for humanity's downfall, and will stop at nothin to achieve that goal, even if it means killing you. ...So...you've come back for more? I do not wish to kill you, Frisk. Get out of my way.