Harem In The Intergalactic Apocalypse - Chapter 19 Rocket Researcher

Due to a bug in the game, Ren Changsheng accidentally left the game idle for ten million years.As he watched the endless stream of experience points, all Ren Changsheng could think was, 'I really do not want to level up!'

One day, Luo Jian woke up from his sleep and found himself in a locked chamber where the door and window were all sealed. A note with a few lines written on it was tacked to the wall: “Escape from this room within an hour, otherwise, you will die.”

There is a sequel called Reincarnation Night (轮回之夜) that takes place in the same universe but has different main characters

- Description from Novelupdates

Freshman student Yang Dingtian possesses the Nine Yang Body, found only 1 in million. His Yang Fire is incomparably vigorous and thus, he cannot be near a female’s charms for his entire life. On the night of his 19th birthday, he decided to bid farewell to his virgin life. After stealing and tasting the forbidden fruit, he spontaneously combusted as the result!

In death he crossed over to another world; a world that held respect for Martial Power. His, originally, catastrophic Nine Yang Body was the Nine Yang Body that couldn’t be seen in a millennium! He was saved by a mysterious old man when he was at his last moments and the old man received him for a disciple, then betrothed his daughter to him. Thus, in this odd way, Yang Dingtian became the successor of the largest clan under Heaven, and became the number-one-beauty-under-heaven’s fiance.

- Description from Novelupdates

There came a sudden ravage by monstrous creatures in a civilian world, leaving humanity's hope to lurk in shadows. Hunters, trained in special schools, wield potential and abilities that enabled them keep the beasts at bay.For Buji, life’s difficulties stem not from being an orphan, but from relentless bullying. Nicknamed “the weakling,” he detests the label but bears it forcefully since he could do nothing.When he transfers to a new school to join his foster sister, Buji thought things would be different. But, during the Awakening Ceremony of the school, he find out a shocking truth: he's was going to be an S-Rank hunter without a talent.Awakening no talent only added more difficulty to his life struggle as he was branded an outcast.On the verge of death during his first raid, Buji awakens an enigmatic system.[Host Found][Survival due to inheritance][Congrats, you have gained the status of a 'player'.][The player, upon leveling up will awaken a potent monster][Class: Animagus | Type: Snake | Aspect: Venom][Do you accept?]Given the choice to embrace a monstrous path, Buji seizes it with unyielding resolve.'If becoming a monster is my only path to strength, I’ll take it—and the world will regret casting me aside. Fighting against these hunters was going to be a job, but imagine a world where I had control over monsters, had my own monster kingdom, and becoming the strongest of all. Stepping on these hunters won’t be a deal anyway.'“Yes!”