I am the Demon king

The war between humans and demons has been raging for thousands of years, and you are the sole survivor of your kind.
The demon race was dispersed over the world after the demon king was killed.
Since the death of their protector, demons have been hunted like beasts and monsters.
This is the tale of a young boy who didn't want to participate in all these wars, but he had to.
He decided to become the new demon race's king—the Demon King—and defend them.
"I'm going to be the Demon King."
But how would he bring all the demons together, given that the world was split into power blocks?
Demons started fighting among themselves, making more of their kinds fall.
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Mc is neither a villain nor a hero.