Fate in Bleach: Unlimited Blade Works! - Chapter 31: Agreement

To save a doomed fantasy world, I killed the main characters, then destroyed the game world, and fell into another timeline as the academy's top seat and rival to the protagonist.Now, I'm trying to save the world and steer it towards a better ending…But I'm the final boss.

Weiss is an ordinary young man caught in the changing times who is studying magic from an unknown natural event. When he feels weak and helpless in facing a world that is constantly changing and filled with magic, he awakens his secret ability, the “Maid Order”. Special abilities that make him a “Master” who will be respected by the “Maids” who are loyal to him.

A man was transported to Ancient China and eventually became a servant of a declining household without a male heir. He utilized his wits and modern knowledge to help the household and eventually become trapped in the sea of political turmoils of the period.

- Description from Novelupdates