The One Who Writes Existence - Chapter 4: Multiverse 9008

Over a million years ago, the first human contracted with the first Spirit. Ever since then, Spirit use has become commonplace. Humans used Spirits to carry items and start fires. Eventually, even start wars. Thousands upon thousands of years past and one day, one human did the impossible. He transcended his mortality and ascended to the realm above.

A Hentai World is a Dangerous Place, Especially if Your Best Friend is a Hentai Protagonist and You Are a Trap.

WOULD. SMASH. BROTHER, HEAR ME OUT...Reincarnated as the lowest life form... a worm. After her husband beat her to death for failing to bear children, Madelaine is reborn carrying deep regret and a life stolen by fate. Even as a worm, she is driven by one desire: to regain the ability to reproduce.Through evolution, she becomes a Chimera Mother. With her reproductive ability, she ensures she will have children of her own, filling the cave she lives in. Each child is formed from monster traits she gathers from the world around her. To Madelaine, they are her legacy, the life she was denied.To humans, they are abominations. How far will she go to protect her children from those who see them only as monsters?[No Yaoi, No Yuri, No Harem or Reverse Harem. However, her sons and daughters may have harems.]

He became the villain in the possessed game, the rival of the main character, and the second seat.