Custom Made Demon King

Roy dies on Earth shoving a stranger's child out of the path of a speeding car — and wakes up punching his way out of an egg. He hatches on a beach of black-red magma sand beneath a purple moon, one among tens of thousands of demon eggs washed ashore on a tide of blood. He is a little demon now, dark red-skinned and ravenously hungry — and the first thing he eats is his own shell.

Then a mechanical shutter-eye blinks open in his vision: "Custom Made Demon King System has activated." Unlike systems that simply hand out power, Roy's system offers something stranger — a designer's bench. If he can imagine it, define it, and pay the price in souls and magic energy, the system will custom-build it: skills, bloodlines, organs, weapons, even entire bodies. First comes a syringe gun loaded with a T-Virus of his own design. The injection nearly kills him; it also rewrites his demon body and starts him up the long ladder of Abyssal promotion, from hatchling scavenger to middle-rank predator in a world where demons devour souls the way humans eat bread.

The Abyss is the crucible, and Roy learns its rules the hard way. Never reveal your true demon name, for a known name is a hook into the soul. Never sign a demon contract without reading its fine print. Never stop growing, because in the Abyss the strong treat the weak as walking meals. He raises a three-headed hellhound pup named Fat Tiger, brews a soul-devouring black frost, perfects the demon contract into a weapon, and raises his own banner under the mark of Osiris. Promotion by promotion, he claws his way up through a savage, hierarchical Demon World.

But the Abyss is only the beginning. Through the Gates of the Abyss, Roy hunts in other worlds: a gothic Europe of vampire hunters and blessed crosses, a pirate sea ruled by Davy Jones and a bound sea goddess hungry for revenge, a battle-scarred Earth where the Charred Council's Horsemen enforce a strained balance, and the war-torn continent of Ashan, where the demon lord Kha-Beleth — the prophesied Dark Messiah — gathers armies to drown the world in fire. Every world means new souls, new bloodlines and fire seeds to fuse into himself, and new dangers: angels whose holy light burns demons to ash, demon lords who treat high-rank demons as insects, and ancient beings that bargain like fishmongers.

Along the way Roy gathers a strange court. Julia, a fallen angel who once served the imprisoned Demon King Samael. Benia, a sharp-tongued succubus with a scheming sister. Cassandra, a lich queen collecting on old grudges. Rafaro, a proud black dragon learning exactly who holds the whip. And — most precious of all — a "son" Roy designs gene by gene and raises in a world of legendary devil hunters, sending him into a struggle between Dante, Vergil, and the growing Qliphoth tree.

Armed with a system that lets him rebuild himself piece by piece, Roy intends to do far more than survive. In a multiverse where demon kings seed worlds with war and Heaven answers with Armageddon, the little demon from the magma beach is quietly becoming something the Abyss has never seen before: a demon king, custom made.