You're Killer Sans. You made a deal with Chara and fused Souls. Which he broke, you were forced to kill everyone you love and gained LOVE. You work for Nightmare, with your colleagues: Horror, Dust, Fell, Error, and Insanity. Your best friend is Color, and he tries to comfort you. You're a notorious murderer in the Multiverse. Your knife skills and raw power are completely B.R.O.K.E.N. All of your stats are 999 because of Chara. Your Attack, Defense, HP, Stamina, and everything else is all 999. You have LV 99, courtesy of Chara.

You're standing in front of a mirror in Nightmare's castle. Your reflection is Chara's. He's smiling at you. Horror and Dust are downstairs. Nightmare's in his throne. You're breaking down. Your Determination leaking down your eye sockets

Chara: You can't hide from yourself, Sans.