Transmigrate and Become the Lord of Monsters

Huh? I finally reached max level in a game and became a great demon king. I was going to teach those players who didn't know their place a good lesson for picking a fight with me, but who could have guessed I'd transmigrate just like that? And why is this otherworld so much like the game I used to play? Not only that, but after transmigrating, I'm still level 999, max level? This... is a little... terrifying...