MTL - Undying Patient - Chapter 187 Puppet Emperor 4

A skilled but unfortunate modern-day assassin was killed in a freak accident. However, he soon found himself summoned to another world by an evil wizard, who had him possess the body of a boy as an experiment. After successfully planning the evil wizard’s downfall, he used the wizard’s body as a springboard to gain influence and power in his new world.

- Description from Novelupdates

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.

As a handsome guy with fame and wealth, Eddy could lay his hands on any beauty around the world. Unfortunately, his little brother down there was too weak to grant him such a wish. What happens when he transmigrates into a body whose little brother is always strong and prepared?He's going to create a harem and indulge himself, right?Sadly, it's not like on earth where every girl admires him. It's a world haunted by darkness and hunger, cruelty and self-centeredness. A world where he is a disgrace to his family. Monsters, among which there are the Venomous Beauties, roam its corners. He is too weak to even play drums, let alone hunt those monsters to win hearts of girls.Thankfully,[Hello! I'm the Goddess of Beauty! Nice to meet you!]#No yuri#No NTR#Spicy

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