Reborn Invincible, I Only Want to Raise Female Disciples

"Master, I want to be a hero. How do I become one?"

"My disciple, listen. You have to become a villain."

"No, I want to be a hero."

"You can't. You have to become a villain."

"I don't care. If you won't let me be a hero, I'll destroy your harem."

"Don't! Fine, I'll teach you how to be a hero. To become one, you need a villain to defeat."

To make his beloved disciple a hero, I, Loki, gave up being human.