MTL - Waiting Upon You - ~ Act Sixty-Three Lies

A recurring nightmare afflicted Khan's nights since the Second Impact. His dreams replayed the scenes of the crash of the Nak's spaceship, an alien race that the humans had defeated five hundred years ago.

Scheming female assassin transmigrated to become the weak Eldest Miss, her story is wonderful and stunning, attracting peach flowers to blossom open. Cold calculating emperor? Genius bad crown prince? Insidious happy-go-lucky prince? Gentle physician? Ice-cold mystery male? Who is her true love? Haha, but she only eats, definitely will not take responsibility! Beautiful men be careful!

- Description from Novelupdates

In a distant future, the empires of mankind span the galaxy, and glorious Earth has devolved into a peripheral backwater.

In Shanjing city in the Asian region, Wang Zheng’s dreams of becoming a mech pilot are crushed when his college entrance exam genetic score turns out a pathetic twenty eight, barely above an animal.

To make things worse, people get the impression he attempted suicide after being rejected by the campus beauty.

Then the closest thing to a family he has, the old man in the book store across the road, goes missing, leaving him only a mysterious birthday present.

- Description from Novelupdates

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