Alpha's Rejected Mate Returns as Queen - Chapter 648 A Mistake

Aldric, a young man from a remote village who doesn’t know much about games is forced by his dorm mates to play the latest and most popular virtual reality game — Magician Online, a magic-themed game with a magnificent medieval world. Armed with curiosity, he played the game without serious intentions. However, unbeknownst to him, he actually awakened the most supreme talent in the game.

“A cheat system? Do you take me for a fool? Nowadays, where can you find such a good thing falling into your lap? Scram from my head. Is this is new kind of fraud? Or is this a murderer training system of aliens that contains the ability of hypnotism?”

“No, I am the chaos that whispers from nothingness, the nightmare of all living beings in the Southern Ten Stars, the successor of the unparalleled God and… your elder sister.”

“…I only have a younger sister, I don’t have an elder sister!”

“No, you have one. I am an illegitimate daughter. It’s just that your dad didn’t inform you.”

- Description from Novelupdates

The protagonist of a war fantasy novel, Theo, competes with his rival and antagonist, Luke, for the position of Supreme Commander. Having been reincarnated into Luke’s role, he struggles to fulfill his duties as the villain. “It seems like principles as a soldier, the duties I should uphold, don’t matter to you at all.” Even if misunderstood by Theo, Luke silently remained faithful to his role as the antagonist. After completing all his duties, Luke successfully gave Theo his happy ending, cast aside his military uniform, and retired from the army. Now, Luke planned to create his own future story without interference from anyone. That was the plan, at least… “Why go this far? I’m no longer a soldier, and if you really think about it, we were never on good terms anyway.” To make matters worse, not only had he unexpectedly reunited with Theo, but now, Theo was persistently and seriously pressing him in a way he hadn’t imagined. “I want to know you better.” It was a completely incomprehensible statement, and it wasn’t even an appropriate answer to the question. The protagonist came to the antagonist and suddenly asked for help, simply because they wanted to know him better?

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