Isekai de Kojiin wo Hiraitakedo, Nazeka Darehitori Sudatou to Shinai Ken (WN) - Chapter 114: Duchy of Lutzbergen.

The little princess of the Huo family, one of the wealthiest families, was mistakenly switched out nineteen years ago! The fake heiress is well-educated, talented, and doted on, while the real heiress is an uncontrollable girl who loves to fight, has a strange personality, and had dropped out of school very early…

A master assassin transmigrates into an interstellar era.

Other players were responsible for competing in the e-sports arena, while he was responsible for stringing up and beating up the other players.

His sword was hidden during the peak of day, and he was a gentleman who arrived in a flash of light;
As a vanguard of the eternal night, he was the variable between life and death in the world.

“As you know, the Star League’s difficulty levels are arranged in this way:
Paradise < Simple < Normal < Difficult < Nightmare < Hell < [Tyron Odin]”

- Description from Novelupdates

Thousands of years ago, humankind left the Old World. We enter a new age where science and magic are no longer opposing concepts.

With these new opportunities came danger in the form of the Dark Races and the ones that named themselves Gods.

However, if there was one thing humans were good at was their ability to destroy. Humankind fought and carved a bloody path into the new world.

Cain’s luck had never been good, but his destiny changed forever once he decided to harden his heart and face the world without fear or hesitation.

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