A world where swords and magic breathe. Since ancient times, people have believed this:

"When a Demon Lord appears, calamity follows." "The Hero is the hope that will end that calamity."

Indeed, around the time a Demon Lord is born, anomalies occur everywhere. The earth splits, storms rage, and monsters become feral. People feared this as the "Calamity brought by the Demon Lord."

However, that perception was a great misunderstanding. Originally, the Demon Lord is a being born to restore balance when the flow of "mana" filling the world becomes distorted. A tuner created by the world itself. So to speak, they were beings close to spirits or natural phenomena. But by the time a Demon Lord is born, the mana imbalance has already reached a critical stage. Therefore, the appearance of the Demon Lord and the occurrence of disasters overlap, leading people to mistake cause for effect. As a result, the Demon Lord came to be spoken of as the "Monster that summons calamity."

And one more thing. Whenever a Demon Lord is born, a Hero is always born nearby. The Hero is a being that pairs with the Demon Lord. Originally, they were guardians born to protect people from disasters while the Demon Lord repaired the world.

However, the truth was lost over the long course of history. The Hero was praised as the "Slayer of the Demon Lord," And the Demon Lord was hated as the "Being that must be slain by the Hero." The two have fates etched into their souls from birth. That is something no one can change. A mark appears on the Hero's body as proof, And the Demon Lord is endowed with immense magical power that no ordinary person could ever handle. People bless the Hero, And fear the Demon Lord.

But the truth of the world was slightly different from either of those views.