Villains Regret That I Transmigrated With Omnipotent System

The protagonist lived an ordinary life until one day, he was possessed by a body-hopping cat that forced him to jump into a river. When he woke up, he found himself transmigrated to another world—a world rotten to its core, ruled by a magic-based class hierarchy and devious villains, the overlords of this realm.

To his delight, he unlocks a powerful ancient spirit that fuses with his generic system skill, forming the Omnipotent System.

Hoping to find his way back to Earth, the protagonist initially struggles just to survive. However, as time passes, his goals shift toward fixing this corrupt world with the help of his overpowered Omnipotent System—all while building a harem along the way.