Return of the Demon Archmage [OP MC, LitRPG]

Three hundred years after the fall of the Scourge Empire, the world believes a simple story: Dark Lord Kaelen was defeated by a hero of prophecy, the age of darkness ended, and peace flourished. The story is wrong. Kaelen returns centuries later, with a festering wound in his side and a chip on his shoulder. The all-powerful archmage sees all of his accomplishments reduced to nothing: the empire he’s built is now a small kingdom, his fortress is a tourist attraction, and his enemies have written him out of history books. Forced to rebuild his strength in this strange new age, Kaelen must uncover the truth behind the battle that supposedly killed him. * * * * * This is a classic OP MC tale with light LitRPG elements, inspired by Overlord, Frieren, Record of Lodoss War, The Wheel of Time, and the Malazan series, among others.