Gospel of Blood - Chapter 13: Charlotte Gathering Snacks

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

Shiao Yi is an 18 years old boy from a war-torn future, he is badly injured while escaping his enemies and wakes up in a strange, old-fashioned world with no technology—only magic, swords, and monsters.He’s saved by a kind but mysterious knight named Dominic and taken to a stone fortress where people think he’s just a lost child.As he heals and tries to hide who he really is, Shiao Yi slowly realizes he may have ended up in another world.With no idea how he got there or if he can ever return, he must learn to survive, understand magic, and figure out if this strange new place could be his chance to live a real life—for the first time ever.

This story is set during the end of the Sui Dynasty, a time where multiple powers struggled for supremacy and power.