Maou 2099 

The year is 2099, Shinjuku City. The legendary Demon Lord Beltre has reappeared in this future city that has achieved ultimate development. The glorious prosperity of the giant city-state and...... the terrible "darkness" hidden behind the scene. In order to rule the new world, the Demon Lord is moving into the future! (Source: ComicWalker, translated) Note: Only the first part of the third chapter was released before being removed.