I'm Quitting Heroing

When Demon Queen Echidna launches an assault on the human realm, the kingdom’s last hope rests on Leo Demonheart. Gifted with overwhelming strength, Leo crushes the invading forces with ease and averts catastrophe—only to be met not with praise, but suspicion. Feared for the very power that saved them, he’s cast out by the people who once relied on him.

Drifting without a place to belong, Leo learns that Echidna is rebuilding her demon army and heads to her castle, betting that demonkind might offer the acceptance humans denied him. Echidna refuses outright, yet Leo finds a foothold by persuading her four generals to take him on in secret. Under the guise of a masked dark knight called Onyx, he tackles the demon army’s day-to-day crises and quietly improves life around the fortress, all while pursuing the answer he can’t let go: what drove Echidna to start the war.