Erotic Adventures in the Omniverse: Vampire Lord got too many wives - Chapter 6: Astrion Prison

Akira Kuromiya is just an average high schooler who gets killed by a robber. He wakes up and is now a chicken!? Even worse he becomes the familiar of a girl who's apparently the heiress of a powerful clan.

That was for a short while though, as he was abandoned and woke up to find out he, now she, is trapped in a deadly magical forest with all sorts creatures trying to kill her.

The world she finds herself is one of magic and monsters like the manga she's been reading. Akira, now Hinotori is trying to live her life as a chicken in another world!

Her – a glutton without troubles or worries who crossed over and became a young fat chick with a deep vengefulness.

The sky thunders, Fang Yue, the nail household, dies on the street, the heavenly court blackmails, obtains compensation, reincarnates, and sees how Fang Da Devil disturbs the universe and upset the world.

- Description from MTL

The protagonist, Winnie (文尼), confesses his love to his childhood friend—the princess he’s been secretly in love with for years—but is brutally rejected in public. His heart shatters, he’s humiliated and ridiculed, and he collapses unconscious. When he wakes up, he vaguely remembers his past life’s memories and realizes he has transmigrated into the world of an otome game he played before. At first, he’s thrilled, thinking, “Nice! I must have been reincarnated as a villainous side character who disrupts the protagonist’s romance, right?” But then… surprise! He’s not just the villain—he’s the “Saintess”!