The Emperor Reigns Them All - Chapter 473 - Hero, You Can't Die

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

I finally managed to kill the demon lord.

“I'm sorry, Kiara,” he began, his voice heavy with regret. “We regret to inform you that we can no longer administer these drugs to you.”I was dying. I was going to die.Kiara Williams was dying from Stomach Cancer. With only a few months to live, she could only stay at the hospital.Alone. Her annoying husband did not come and visit her, only her best friend, Jessica remained by her side. She could no longer pay the bills and was sent home.Arriving at her house she caught Jessica and her husband together in bed. In a fight, her husband pushed Kiara down the stairs.Kiara died.Or did she? She was reborn ten years back, but rather than being destroyed, she begged a strange man for a one night stand unless she may die again.

A mental patient, or a born policeman?

A peerless genius, or a master of crime?

There are cops who are least like cops, and there are criminals who are least like criminals.

Neither good nor evil is absolute.

It is a grey world we live in.

- Description from Novelupdates