Aku

Aku was cast out of her village as a sacrifice to the Devil King Greol; however, as she is being chased through the forest by Greol, she comes to a clearing where she encounters a mysterious man. This man defeats the Devil King with a single knife, causing Aku to become frightened for her life. The man assures her that she has nothing to worry, he introduces himself as Hakuto Kunai. Aku repeatedly refers to Kunai as "Demon Lord", which he tries time and time again, to tell her that's not his name. He eventually gives in and lets her call him the Demon Lord, as they begin their journey together.