Monster Factory - Chapter 578

When a prostitute dies and awakens in the decadent golden city of Prismillya, he finds himself at the bottom of a brutal underground caste system where slaves are ranked, owned, and traded like currency. Reborn in the delicate, cursed body of Loona—a femboy succubus marked as “Guttermeat”—he’s locked in the lowest level of a prison brothel-city ruled by lust, power, and cruelty. But Loona has one secret: with every body he conquers, he steals a piece of his partner’s strength.Armed with wit, seduction, and a thirst for revenge, Loona decides he won’t just survive this hell—he’ll fuck his way to the top.------------------------------------------------------------------[WARNING: R18+ CONTENT INCLUDED]Additional tags: Dark Fantasy, Femboys, Erotic Fantasy, Smutty Isekai, Gothic Dystopia, Prison Break, Queer Fantasy, Slave System Hierarchy, Fantasy Erotica, Magical Realism

The doomsday fell upon the earth when a dragon coffin sealed under a snow mountain for ages shifted, and the civilization of gods and devils began. The whole universe turned into a fantastic new world where everyone could rise to the top through cultivation. A lucky young boy seized the opportunity, and started his journey to be an overlord in cultivation.

- Description from Novelupdates

In the early world of immortal cultivation, there was no physical cultivation among immortal cultivators. And a top bodybuilder who came from the earth has opened up a new path here and became the ancestor of physical training.

- Description from novelbuddy

Based on the popular Vocaloid song .

Rin, a young angel (presumed female, but angels don’t have clear genders) falls in love with a young human girl, Miku. However, their love is considered taboo, and so, Rin makes a deal with the devil to be reborn as the human boy, Len, in order to be with Miku. However, their happiness together is short-lived, and even that soon ends in tragedy.