Damn, I Have to Marry the Strongest Antagonist at the Start?

In the anime world he designed, Owen awakens at the edge of an arena. A coldly beautiful sorceress surveys the crowd with arrogance. The system activates: challenge the stage for god-tier rewards or back out and lose half his HP. He chooses to fight—earning the Merlin talent for tenfold leveling, Mana Void that nullifies all magic, and the shape-shifting Godslayer Staff. But when the system orders him to marry the strongest female antagonist or lose all HP, Owen realizes this transmigrator’s adventure is far from a simple power fantasy.