My OP Minion System in the Apocalypse - Chapter 217 Bountiful Spread

Zheng Tan somehow returns to the year 2003, turning into a black cat. Picked up from a rubbish heap by the Jiao family, he is given the name “Charcoal”, and so begins the life inside Professor Jiao’s family. Zheng Tan remembers that he was once a person, but currently his body is that of a cat. He has no way of speaking the human language, but can understand it, and even retains the thinking and IQ of a young 20 year old youth. Read along as he adapts to this new world, and somehow tumbles from a group brawl to catching a thief.

- Description from Novelupdates

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

Transmigrated Become Sukuna, but the host is Yukinoshita Yukino?“Ryomen Sukuna? The strongest sorcerer in history? He’s just an ordinary person born in a time without me.”Hayashizaki stood in front of Ryomen Sukuna, looking at him with a playful expression.“On my left is the 'Little Yukinoshita,' a possessor of multiple techniques, easily wielding both the Limitless Cursed Technique and the Ten Shadows Technique; on my right is the 'Big Yukinoshita,' who has awakened a unique modern technique, no less powerful than me. As for slashing techniques, those are just our basic attacks.”“So, tell me, how do you, Sukuna with 15 fingers, plan to deal with this?”Ryomen Sukuna stared at the black-haired young man in front of him, whose cursed energy was identical to his own, dumbfounded.

Zhou Peng accidentally travels through time, finding himself in a weakened and sickly body with a shattered dantian, unable to cultivate qigong. Fortunately, the heavens show mercy by bestowing upon him an upgrade system.A waste? That's all in the past...Leveling up by slaying monsters, effortless and hassle-free, he no longer has to worry about cultivating.Killing monsters grants upgrades, and so does killing people. In the eyes of others, the awe-inspiring and prestigious sect masters are nothing but shining golden bosses in his sight...With the ability to upgrade, who am I afraid of? When so-called geniuses encounter roadblocks and fail to breakthrough, all I need to do is slay a few more beastly demons. Of course, sect heads, sect masters, realm lords... are even better.For the sake of my path to divinity, offer up your lives!