From Idler to Tech Tycoon: Earth - Chapter 56: Testing

On the distant Tianxiu Planet, there exists a group of unusual and intelligent beings. They consist of neither children nor elders. They have neither birth nor real death. They are born into the world through an extremely special process and have managed to keep their fundamental memories of survival through their endless reincarnations.

They are the Tianxiu people.

For every Tianxiu person, if they find someone they like and want to bind as partners with each other — then they would have to go through a life or death Adult Ceremony. The winner of the ceremony will become the absolute dominant in this spousal relationship.

While the defeated one will be referred to as — Qizi.

- Description from Novelupdates

Drugged one night by her ex-boyfriend, a mysterious man took advantage of her in an ecstatic night filled with sex.To take her revenge, she married the man, and used him.

Roy’s life was nothing special. The only thing commendable was the last few moments when he saved a mother and her child from a drunk driver.
…
It’s really an egg! Damn it, what kind of monster have I become? Did I fall into Hell instead of making it to Heaven??
Join Roy as he ventures through various worlds with the Custom Made Demon King System—a system that allows Roy to draw anything he can imagine and create it through exchanging souls!