Rest in a Demon's Embrace - Chapter 199 - Illegitimate Child?

Being given a chance and reincarnated is nice and all, yet why do I have to become that male friend who just watches the protagonist flirting with his harem?---World: Kaguya-sama: Love Is War - Hyouka ----

Wu Lai was an ordinary high school student. One day he was struck by a flash of lightning from a different world, and suddenly entered a fantastic world full of magic and swords. Since then, he started a totally new life. In this supernatural world, he had his ups and downs, experienced numerous battles, subdued powerful evil beasts, and fell in love with a belle. His nickname “Demon King” was remembered throughout the ages there.

Stay or return was a question. In the face of this choice, Wu Lai, with the nostalgia and gratefulness for the original world, finally chose to stay…

Here was the legend of “Demon King”…

- Description from Novelupdates

In a world where strength is measured by the beasts you command, only a few ever reach the peak — and even fewer survive the journey beyond it.Aether was just an orphan in a forgotten city, someone with no family, no background, and no future. During the Beast Contract Ceremony, everyone expected him to fail… or at best obtain a weak creature.Instead, he formed a contract with what appeared to be the most useless beast of all — a Fire Pup.But what no one knows is that Aether possesses a power that should not exist.His beasts can evolve without limit.While others struggle for years and risk their lives to gather rare materials, Aether’s beasts grow stronger simply by fighting beside him. As he rises through factions, battles powerful enemies, and unlocks ancient evolutions, the truth about his mysterious origin slowly begins to surface.Hidden bloodlines.A sister imprisoned by the rulers of evolution.And a secret tied to the legendary Ascension Gates that connect three universes.What begins as the journey of a forgotten orphan soon becomes something far greater.Because the Fire Pup that everyone mocked…Was destined to become a Hell Cerberus.And Aether was never meant to be ordinary.He was meant to become the Beast Monarch.---

The world was split into several different realms, each of this realm filled with perilous dangers and Monsters that many would say came from the depths of every nightmare ever dreamt by man.Those that perish in this realms die in reality but those that survive will come back stronger, with special abilities that ruled higher than the normal human could phantom.Humans must transverse the realms to become stronger. Many do it for the purpose of their greed and hunger for power, but others do it to protect the earth as humans can venture into the realms to get stronger, sometimes the monsters from the other worlds can also breach through.Fang Zhen a conqueror in his first life, dies and he is reborn into this world of realms as the son of a Noble Lord. With the goal of becoming the strongest In this world he is blessed with that an especially powerful Ability, an ability born of dragons that might just be his way to reaching the top.But with every great power comes a great flaw, and with every great blessing given to the humans come the greed that rules alongside it.