I Built a Beast Empire After Reincarnation - Chapter 21: Aegis Unleashed

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!

(Isekai, Fantasy, Non-transmigration, Unconventional, Ensemble cast, Meticulously crafted setting, Multiple identities, Light novel, Succubus)I have many masks, and each has its own story.I am the unremarkable little artist of the Church of Dawn; the strongest apprentice in the gladiator arena; the killing machine in the eyes of goblins... The holy nun beneath the sunlight is me, and so is the old gentleman on the train... I have hurried through underground tunnels in escape, and I have left behind beautiful legends on the frontier...Beneath the mask, there is an even more beautiful mask; within the lie, there often lies a hidden truth...My name is Ogre. A child raised by ogre since birth. It's a pleasure to meet you.

The scum’s or villain’s long road of transformation was tentatively set to the world:
The abandonment of the educated youth’s wife (Completed)
The hidden marriage of the scum film emperor (Completed)
The best brother in the world (Completed)
The Phoenix male who destroy the bridge after crossing the river (Completed)
The treasonous general (Completed)
I’m an honest man (Completed)
To become the top scorer in the School of Agriculture (Completed)
The soft rice man’s self-cultivation (Completed)
The whole world is reborn (Completed)
I want to survive on a desert island (Completed)
The stallion male who has seized the opportunity (Completed)
The perverted self-salvation (Completed)
The spring of the loafer (Completed)
The misplaced life (Completed)
The miser career (Completed)
The ghost is out of feeling (Completed)
The Queen’s favorite husband (Completed)
The vicious girl with her godfather (Completed)
I want to be a good person (Completed)
I does not tear up the family (Completed)
The perverted common plant (Completed)
The Mary Sue’s men (Completed)
Every time I was reborn, someone wants to kill me (Completed)
The old people’s counterattack path (Completed)
The global evolution (Completed)
When I became a net red (Completed)
For you, good person (Completed)
His heart had white moonlight (Completed)

- Description from Novelupdates

Birth of the Biomancer:Mio was the worst healer in Tokyo. F-grade, dead weight—her party kept her around out of pity until they did the math and left her bleeding in a ruined cathedral.Something ancient was waiting there. It offered her a Class that devours its hosts—a path of power that claimed the lives of the three Biomancers who came before her. Mio said yes anyway. She’d already felt the sting of a slow death; what was one more monster in her veins?Now pain is currency, death is fuel, and the hunger grows with every kill. The Bureau wants a weapon. Her sister wants her home for dinner. Mio agreed to both.In a world of Systems and Dungeons, power isn't a gift; it's a trade. And Mio is finally ready to pay the price.════════════════════What This Is:[1] This is a progression fantasy with system elements, but the system serves the story, not the other way around. Expect meaningful numbers, not stat spam.[2] Romance is not the focus. Mio has bigger problems. But expect a slow-burn later down the line![3] The story gets dark, but it's earned. No grimdark for shock value.