Planetarium System: The Sorcerer's Sentry

Lai is a Sentry, an assassin that hunts criminal sorcerers in a world much like our own aside from the fact that magic lies hidden from the public's view. He's led a rather peaceful life watching over his city, but chaotic elements start adding up, and it he will find himself fighting all manner of magical threat. From witches to cultivators to dragons - you name it.

The only issue is that he has no talent for magic. However, he does have have something no other sorcerer has: the Planetarium System which lets him host his own personal planet inside him.