Kujibiki Tokushou: Musou Hāremu ken - Chapter 256

After Xia Feng transmigrated, his heart was mysteriously removed.In its place, a defective demon heart capable of sustaining life only for eighteen years was implanted.This is a magical heart that can sync with the power level of its target.To stay alive, he bound himself to the ultimate villain of the future, a Destructive Witch who was destined to destroy the world.The stronger the Destructive Witch becomes, the stronger he becomes!Thus, Xia Feng realized, it's not my fault for stirring up trouble: “Miss Witch, I admit you're strong, but not strong enough!”

Who, in the ancient mythology, held an artifact and killed the first emperor of the human race?

Who, at the beginning of ancient times, closed the gate of the God Realm, Jedi Tiantong?

Who set a lifespan limit of only one hundred and thirty years for the people, and even the Great Emperor was not spared?

Who, turned into a black hand that covers the sky for eternity, shrouded the world?

…

Yang Shou on Earth: “Yes, yes, I did it all, I just want to live.”

- Description from novelbuddy

Sato Yu is a 12-year-old boy. He is a deprived person. His life is depriving. His step father has a large amount of debt.

In a tyrannical world, what is evil? What is benevolence? All living creatures are brutal. Passing through the heaven road to find one’s purpose in life. Struggles to be stronger is not an easy path. The whole journey thistles and thorns, one blade chops open a path, I alone will be supreme!

- Description from Novelupdates