Sage Dwight, who, alongside the Hero, vanquished the Demon Lord.

Despite bringing peace to the world, they were accused of plotting to become the next Demon Lord and were cast down into the Valley of the Dead, losing their lives.

A decade later.

Dwight, having lost his corporeal form, had become a skeleton, quietly lingering at the bottom of the valley.

Wracked with deep regret, he clutched the Hero's remains and pondered.

He then arrived at a single conclusion.

“It is the world that is mistaken. I must reject it.”

With his resolve set, Dwight devoured the miasma of the Valley of the Dead.

He transformed into a being surpassing even the previous Demon Lord, and leading countless undead, he set his sights on the surface world.

All for the sake of true world peace.

――Thus, the immortal king, wielding ultimate power, commenced a war against humankind.