Heretic Doctor Useless Consort - Chapter 1401 - Heavenly Soldiers

When he did not know her true identity, he treated her very badly, he disliked her too much, she was not elegant enough, she was in the way...Only later did he realize that the woman was his legal wife! He repented, tried to recover her feelings, but she was determined to divorce him.

Born naturally defective but possessed by the spirit of a divine dragon. Inheriting the divine dragon’s will and power, growing scales and magical claws, imperial waters containing the breath of the dragon, travelling through clouds and summoning rain, an invincible physical body. In this world and era, countless men dream of slaying dragons. Li Mu Yang has always lived a hard life.

- Description from Novelupdates

This story is centered around the man named Yi Ji-Hyuk, who has spent 1000 years in a Medieval Western fantasy-like world before returning back to the modern-day Earth. When he returns, he finds that his home is facing monster threats, and that humans with superpowers have appeared to protect the innocent people of Earth.

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