Isekai Maou to Shoukan Shoujo no Dorei Majutsu - Volume 10 Chapter 5 part6

Han Yang never thought he would one day sell himself into a marriage with another man. He believed his life would be mundane but that man, named HeLian Qing, broke his pre-planned life. Parental debt, a child’s compensation, he had no chance whatsoever to resist, he has no ability to resist.

A wonder falling down from heaven! A boy possessed by strange blood! Gods tremble! Demons flee! A boy from the land of Dong Zhou. A pink skull as his sworn friend until death. A story of a determined warrior struggling for power. A legend that shakes the galaxy and disturbs the worlds of god, demon and man.

- Description from Novelupdates

I found myself possessing the body of a young master who everyone was eager to kill. I’m invincible, so let them try to kill me. It’s only for one second, though.