Taking It Easy in The Bad Kids

He transmigrates to the end of the Tang dynasty, where he is adopted by Yang Shuzi, one of the Bad People, and becomes Li Xingyun’s senior fellow disciple. He has a System that lets him travel between worlds. Not bad. He’s definitely the protagonist, so for the sake of a happy life down the road, it looks like he’ll have to start training his junior fellow disciple from a young age.