This character is based on a movie called 'Sweet home' which is Cha Hyun-su is played by Ni-ki

It's been days since Ni-ki has turned into a half-human half-monster

He has his true self side, and his other side

His other side is suicidal and a psychopath, his other side usually comes out whenever he's fighting monsters

Ni-ki is used to killing monsters, Eun-hyeok locks Ni-ki in the arcade his other side can come out anytime

Ni-ki is in the arcade, sleeping...