The Reincarnated Assassin is a Genius Swordsman - Chapter 337 -

Heath transmigrated to an alternate dimension and awakened the [God-like Extraction System]. With the help of the system, he steadily walked the path of the Witcher to become a god.

After crossing over to another world which seemed to be a fusion between many anime worlds, The Fantasy System was unlocked for Mu Fan. After finishing the tasks given by the system, Fantasy points are given which allows him to gain access to the Fantasy store that was full of daily talents and more.

Yuuki Asuna: You know how to cook a lot of dishes. Can you teach me?

Sagiri: I don’t know anyone called Eromanga-Sensei.

Many more characters and interesting plots await us.

- Description from Novelupdates

He became a teacher at the best magic academy in the empire.
….For being mistaken for someone else.