Old World Covenant

The Demon King is synonymous with evil and fear. The Demon King is as powerful as a dragon, but he is always defeated by brave men who claim to be righteous. This is how reincarnation is in the world~ He was summoned here by the defeated demon king of the previous generation, and when he woke up he became the new demon king. With the knowledge of the earth, he made himself a different kind of demon king, and planned to re-establish a great empire on the ruins of the Holy Demon Empire!