Apocalypse Descent: Farming with My Harem - Chapter 66 - : Expensive Black Diamond, Purchase Golden Equipment!

This story unfolds during the later stages of World War II, where a man, scarred by the horrors of war, finally grasps the profound and harsh realities of the world. In this world, those at the top laugh and celebrate, while those at the bottom sacrifice their lives in futile conflicts driven by pride and meaningless ambition.A modern soul transmigrates and fuses with the original soul of a body, creating a unique and extraordinary existence. To some, he is a villain; to others, a madman.In a world steeped in cruelty, this man, determined to secure a place among the decision-makers, struggles to break free from the ranks of those powerless to control their fate. To achieve his goal, he resolves to shatter the chains of law, then the chains of morality, and finally the chains of mediocrity.

Xia Yan passed through to the world of Bleach and became an eleven-year-old boy. He was rescued by Renji and Rukia in the Seireitei, and he was studying at Shin’ō Academy, and he was a student of the same class.
He is a top student of the Shin’ō Academy, and he is vying for strength by various teams. In the end, he has entered the first team of secret mobile maneuvers.
He will use punishment to kill every person who tries to threaten the martyrdom and protect his loved one.

- Description from Novelupdates

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!