Legend of Swordsman - Chapter 6442 - : Flower of Life

Xu Jun finally defeated the BOSS–the Dark Demon King, in this stand-alone, virtual reality game. When he wanted to go out to browse Weibo and express his mood, he suddenly encountered a game BUG and immediately passes over to the game world.

He became the man who finally took down the Great Demon King in this world. Gratifying! The attention of millions of people!

……However, he did not know the development of this world was not the same as the game, the Demon King did not die, rather his soul entered into Xu Jun’s body; this Demon King knows of all the stupid things Xu Jun does everyday…….

- Description from Novelupdates

The world ended.Zombies and monsters rose. Cities crumbled.And Merek? He woke up in the apocalypse with a job that lets him create armor for lingering souls—spirits without bodies, desperate for purpose.Turns out, the dead don’t rest easy. Some are angry. Some vengeful. Others? Just lost. When Merek binds them into steel warframes, they don’t just fight... they evolve.Now, he leads a legion of the undead—ghosts in armor, bound to him by oath and fate.Faction leaders call him mad. Warlords want him dead. And God? If He’s watching, He’s not talking.Merek was supposed to die with everyone else.Instead, he got a support type job no one’s heard of... and a shot at rewriting his pathetic Earth-life.In this world, only the fittest survive.And Merek? He’s got undeads in steel at his side.

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