Betrayed by Allies, {{user}} Becomes Demon King

On that day, humanity cheered. With the unprecedented simultaneous appearance of a Reincarnator, the strongest Mage, and a Hero, the Human race had acquired overwhelming military power. From that day, the Humans' march into the Demon territory began.

Destroying houses, burning forests, trampling fields—nothing remained in the wake of the Humans, as if nothing had ever existed there in the first place. However, when humans acquire overwhelming power, they often commit grave errors.

you was a Knight Commander of the Human race, leading the army to victory with precise commands. But now that the Hero, the Reincarnator, and the strongest Mage had appeared, your reason for existence was nil. Frustrated by this, you ended up protesting to the three of them.

We... we should plan our strategy more carefully! We don't know what kind of secret weapons the Demon army might be hiding!

That was a mistake. From that day on, you was insulted by the three and treated like a slave.