MTL - Immortal Emperor: Reborn in the Mixed City - Chapter 5225 Descendants of the yin god

When Simon dies, it turns out there's more to combat than lightning reflexes with his controller, and the path to becoming a hero is more brutal than he can imagine as he descends into The Pit. Death after Death is a dark, time loop/Isesaki story with roguelike elements, that explores some of the common tropes in a different light.

〔Congratulations, for mating with a Queen Bee you got a new achievement: ”Not a virgin”! Your reward: “Drone Consort” title.〕‘Hey! I wasn’t a virgin before this, system!’Imagine that you lived a painfully average life, died by a stupid, stupid accident, but a goddess interfered and gave you a second chance in another world.There, you became a consort of a beautiful, big-chested queen, and your only job is to have mind-blowing sex with her so she could have thousands of your adorable daughters. In return, you can live in peace and luxury for the rest of your days.Which means, for about two months. Because I’m a bee. And my queen is also a bee. And bees don’t live for long.The only way to increase my lifespan is to develop my bee colony. A hard task in this huge world filled with dangerous and hungry beasts, other war-hungry insect tribes, and natural disasters.But I have a hundred thousand daughters, some actual brains, and with superior genes given to me by my system, we will be unstoppable!===Note: no NTR, harem, incest, or outright smut.

Vergil, a 21-year-old young man, leads an apparently simple life in a somewhat troubled world. His family is also simple—although his father is no longer alive, his mother has always been by his side, despite being a bit... aggressive. But that's not so unusual nowadays, right?Everything changes drastically when Vergil, after an unexpected death, awakens as a demon. To his surprise, he discovers that he has accidentally married beautiful Pure-Blood demonesses.Now, he will discover how the world really works from a Demon's perspective.

In novels with a stud there is always a Senior Martial Brother like this:

In the early stages of the novel, his innate talent is high, his cultivation is good, his appearance is handsome, and he has an intelligent, cute younger Martial Sister as a fiancée.

In the middle stages of the novel, he is caught unprepared and defeated by a young disciple (the protagonist) in the sect who’s hardly remarkable at all. From then on, he falls from his godly altar and loses his brilliance. Even his young Martial Sister leaves him for someone else.

In the late stages of the novel, he continues to turn dark, going down the Demonic Path and becoming the major villainous boss. However, the protagonist still ruthlessly defeats him and his soul is eternally sealed.

Once Qin Mo opened his eyes, he discovered that he had become this Senior Martial Brother.

- Description from Novelupdates