Fate's Slave - Shadow Slave X Honkai Star Rail - Chapter 84: Flawless

A teenager named Evan Mason was reincarnated into the magical world of Harry Potter and goes to school at Hogwarts!
With only his knowledge of the future and great talent for magic, he takes the path towards the top of the magic world, only to realize that ever step he took, changed everything!

- Description from Novelupdates

Yuder was a commoner Omega who rose to the top with his ability.

When he woke up again after being falsely accused and executed, he was back 11 years ago before everything began.

A chance to get back……

He must not repeat the same mistake he did before.

To survive, and to save the world, now he had to save the man he had killed!

Finding himself in an Last Airbender without an airbender around, a transmigrator waterbender goes on an adventure to stop the worst from happening to him.

In the original lines of the novel, I was a villainess—used as a political tool by my father and older brother—who ended up dying at the hands of my future husband.