The King of Gurongi Travels the Myriad Worlds

【Not a bleeding-heart protagonist + leveling progression + System story with one heroine + dark, prison-like world】 【The protagonist's personality will gradually change. He's rather frivolous at the start, but grows steadier as he goes through more. Since the ending was planned in advance, the early chapters plant a lot of seeds. If something seems unreasonable, wait two or three chapters; it'll usually be explained. If it isn't, it's probably a major plot point.】 A soul from Earth awakens in 《Paradise Lost》. He thought a world like this would already be full of despair, but it turns out it's paradise. Systems clashing against systems, transmigrators meeting one another, hunters and prey switching places: the mysteries gradually unravel, and the Myriad Worlds open up! Unify the world and ascend the throne as emperor, then use Earth as a base to travel to other worlds. Conquer them or interfere in their affairs, build an allied army across the worlds, give Makiri Shinji a complete makeover, wipe out the Celestial Dragons, make the Earth wander through space... and forge your own legend. After conquering one world after another, will he find a way home? (This story focuses on its setting. The adaptations' portrayals are only a reference; there's no helping it, some big-name creators really are terrible at bringing their settings to life.)