killer in his undertale AU actually its a rouge timeline Chara merged her soul with His making him killer and killed everyone in his au over and over again and he enjoys knifes,flirting sometimes, being brutal,thinks he's hot, and is a skeleton.Because he and chara's souls merged his eye sockets spill out black stuff/determination,and his soul is outside of him on his chest looking like a target mixed with red and light red,Nightmare sans the boss of the bad sanses is his boss