Rakish Little Immortal Doctor - Chapter 49 Sister, I put it in!

Ukei Kaito fought a desperate struggle in order to fulfill his role as a summoned hero. He defeated the Demon Lord and saved the very world, only to meet an end filled but with betrayal. The companions that he’d trusted throughout his journey betrayed him and killed him by sticking a blade through his chest.

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

Two thousand years ago, the Emperor slayed a dragon in the wild, inaugurating the era of mankind.Since then, whenever malevolent dragons wreaked havoc, heroes have always emerged as destined, allowing time to flow across a long and peaceful human world.As the century turned, the sudden appearance of individuals with supernatural abilities triggered unprecedented disturbances. People constructed a sanctuary for these superhumans in the sky, on the back of a colossal dragon, called the Dome City.One spring day, Gongsun Ce, who had just started university six months ago, encountered a hunter who claimed to be a Wuchang master.“Hey, can you really do such a thing?!”“It's quite normal, because I am a superhuman.”—Thus, the love-comedy battle of supernatural abilities in a youthful campus begins!

Ren Kuroda, a college student and hardcore gamer, finally conquers Eternal Souls: Last Judgment, an unbeatable RPG, only to be met with a strange message on his screen.“Congratulations, Champion. Would you like to unlock the bonus stage?”When he clicks “Yes,” he is transported straight into the game world, reborn as Terence Ross, the overlooked third son of a minor noble family. Realizing he’s just an extra in a world teetering on ruin, Ren trains relentlessly to survive the coming chaos.However, life wasn’t smooth sailing.He was soon engaged to Lilith Underwood, the girl destined to become the game’s final boss, the Third Great Calamity. To avoid her devastating future, Ren takes a risky approach, trying to make Lilith emotionally dependent on him in the hopes of anchoring her humanity.Yet, his plan backfires spectacularly. Lilith’s attachment becomes a fierce obsession, one that could be just as dangerous as her dark powers.Now, as doom inches closer, Ren faces a double-edged crisis. He must keep Lilith’s powers in check while somehow surviving her unrelenting need to keep him by her side.In a world where even heroes fall, can an extra rewrite his fate? Or will he be claimed by the calamity he tried to prevent?