The Grim Loop Of Destiny - Chapter 15: False Salvation.

This is the story of Kir, who has to thwart the will of Heaven, Hell, and his parents in order to survive, protect the people he loves, and achieve happiness.He just has to make it through life at a magical academy, avoid dying, and survive to find his birth mother, the lost Daughter of Heaven. Or be forced to take his place at the side of his father, a Duke of Hell bent on destroying the way things are.It's a lot to handle for a quiet, brooding angel boy.Fortunately, he has company. A succubus, a foxkin girl, and a half-angel boy to start. And Kir has his own secret: this isn't his first go at life.

Shion, the ‘Hero of Darkness’. He was said to be the strongest hero ever. He believed one thing, and that was his current party members.

“I’ll defeat the Demon Lord with this party!”

That is what he swore to do, but a tragedy occurs. He was painfully betrayed by the girls that he trusted.

He barely held onto his life, but the incident left a deep scar in his heart.

He gave up on living, and while he was wandering around in a forest, looking for a way to die, a single monster appeared in front of him.

“Will you kill me, please?”

The monster asked Shion, who was still strong, despite losing his powers.

What Shion, who wanted to die as well, did was―

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