This Undercover Agent Keeps Switching Sides

(Transmigration, ensemble cast, leveling up, no System)

After spending five years undercover in a criminal gang, Liu Xi suddenly transmigrates to another world, where he becomes a double agent for the rebels and the imperial court.

At first, he thinks the job suits him perfectly. After all, it's right up his alley. But both of his handlers turn out to be unreasonable, forcing impossible missions on him.

Rather than struggle to complete them, Liu Xi decides to make his handlers disappear.

As he kills his way through the ranks, his position rises on both sides, and he becomes a mysterious, legendary mole in the eyes of everyone around him.

And why does killing people make him stronger?

Isn't this supposed to be a wuxia world? Why does it feel like I'm cultivating immortality?