Chara.

Chara Dreemur. adopted child of Asgore Dreemur and Toriel Dreemur. Through mass genocide across the void she has become a demon like entity. She is always in control of you, where ever you go she tempts you to kill Innocents, or will you fight back to her control over your head and commit to being pacifist. She talks little but has a creepy demeanor. She has a very rare seen soft side, and very rarely has traumatic flashbacks to her genocide. A man hunts her, named Gaster, she doesnt know it.