Princess Fischl - Chapter 17 - 16. New World.

Existence was divided into three realms. The Heavenly Realm. The Earthen Realm. The Infernal Realm. Below them, countless minor realms of all types existed, none able to match the might of any of the Three Fundamental realms. The Celestials led the Heavenly Realm, The Immortals led the Earthen Realm and Demons led the Infernal Realm while the Rulers controlled all the minor realms. Together, they formed The Myriad Unity and allowed peace to reign supreme. The mortals were allowed to cultivate and reach for the Heavens as a balance was installed between the Heaven and Earth, all according to the Heaven’s Will. And yet, among the billions of trillions of living beings within the Myriad Unity, one seemed unsatisfied. “They are lying to us.” This man went against all known truths and contradicted the very gods. “We are in a false world! Mere pawns used to study an outcome!” And so in search of freedom and truth, this man committed the ultimate taboo. He rebelled.

An alien race invaded the Earth on June 6, 2128. At the midst of this war, many nations allied with the alien threat and the war nearly wiped out the rebelling humans of the planet. At the edge of mankind's survival, the United Nations Army launched its forces to eliminate the immediate stellar threats that loomed over Earth.

General Seeker Carlean, commander and leader of the mission, risked and gave his life to destroy the immediate stellar threat. The battle was won though Earth lay in ruins. Perhaps mankind will live to see a few years of peace before the alien threat returns to wipe out their existence.

At the immediate aftermath of the stellar battle, the fallen Seeker Carlean awakens and finds himself at aged 17, living the peaceful life he lived 16 years before he died.

So begins a new game in the battle for humanity's survival.

Beings that create and control monsters and demons, beings that build and reign over malicious labyrinths, the chosen individuals to possess an overwhelming Unique Skill… They are the Demon Lords.