Sealed for a Thousand Years, Then the System Came Knocking

In a collapsing universe, an unknown black three-dimensional cube has taken the place of the sun.

Inside the black structure, darkness covers everything.

A woman appears in the darkness. Her beauty is breathtaking, but the terrifying aura around her makes even the gods tremble. The dragon horns on her head reveal her identity.

The Demon God: the first, the strongest, the only Demon God. She commands evil, all the evil in existence.

Because her power continued to grow, the gods sealed her away in this world.

Then, a few thousand years ago, a new demon arrived here.

He was a true demon.

No one knew his power, identity, or race. Even the gods could not see where he came from.

He was truly...

Unknown!

This novel and its characters are entirely fictional. Any resemblance to real people or events is purely coincidental. Do not imitate.