In the Ultraman World, but I Am the Shadow Monarch

After accidentally transmigrating into the Ultraman universe, Cheng Yuan becomes an artificial lifeform created by the Ultraman Killer and the lowest-ranking enforcer in the Dark Alliance. His first mission is to eliminate Tiga and every monster in Tiga's universe. Just as Cheng Yuan thinks he's about to die, he suddenly awakens the Shadow Monarch panel. Every monster he kills grants him experience to level up, and he can extract their shadows to use as his own. Thus, a Shadow Monarch rises. “Get up.” Years later, deep inside the Dark Alliance headquarters, now emptied by a massacre, Cheng Yuan speaks a single sentence and countless dark powerhouses bow before him in submission.