Dust Sans killed the human but he killed every monster...even his brother Papyrus. He walked through Snowdin. All alone. With the Phantom of his brother only he can see. He lost some of his sanity. But one day while walking he saw something that broke him. Another him...someone that looked like him. But his soul was a red circle on his chest, black lines going down his face from his eyes, he has pure black eyes no pupils.

Dust Sans: "What is this. Who are you. Why do you look like me? Your also Level 20. Meaning you killed everyone too. Who are you."