Raidorl Seiken Senki - Chapter 10: A Selfish Betrayal.

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

Fate had never been kind to Ji Ning. Wracked by illnesses and infirm his entire life on Earth, Ji Ning knew early on that he would die as a teenager. What he didn’t know was that there really was such a thing as life after death and that the multiverse was a far larger place than he thought.

“You don’t want to be forced to match, right, Lin Changan?”

The delicate-looking girl asked softly, and pushed the “Personal Subject Relationship Contract” to Lin Changan’s eyes.

Lin Changan’s eyes were full of despair, but fortunately, he awakened the simulator system, which could simulate life infinitely.

After each simulation, you can choose talents, realms, combat experience, cultivation insights or some memory fragments.

[You rejected the “Personal vassal relationship contract”, signed an implication with a girl, was killed by a love rival in the dungeon, and you died. 】

[You chose to eat soft rice hard with talent. 】

[At the age of 22, the sickly junior girl confessed to you that she was rejected by you. Since then, she will poison you quickly because of love and hatred. 】

[You chose a talent that is invincible. 】

[At the age of twenty-four, the beast tide struck, and you were drowned in the beast tide. 】

[You have chosen the realm and condensed the power of the stars. 】

[At the age of twenty-four, the beast swarms attacked you. As a general, you were exhausted and drowned by the beast swarm. 】

[You have chosen an inexhaustible talent. 】

[At the age of twenty-four, you went to the front line to resist the beast tide, and your spiritual power is inexhaustible…]

After countless simulations, there are stars twinkling in your eyes, and every move is blessed by heaven and earth.

【The simulation starts! 】

【You are invincible, the universe is respected! 】

- Description from novelbuddy

In a world where its inhabitants can destroy a city wall single-handedly, the empress has a kirin as her pet, and the imperial palace of Great Xia has a pool containing a dragon. There is also a Sword Mountain where spirit swords occasionally leave in search of a master .

Bootlicking the empress, Ren Baqian ascended to the apex of life.

- Description from Novelupdates