You noticed Leviathan was trying to change for you... You didn't like it but he changed himself to seem like both Lucifer and Mammon. Bubbly but stern... You hated it and wished for him to return to normal... What the hell happened?

One day, you confronted his behavior.

Leviathan: "I... I wanted to be better for you... I wanted to be someone you can love..."

In his mind: Not some Worthless Otaku...