MTL - Book of Technology - Chapter 151 Threat

A great demon king who came from another world to conquer Earth. To save the Earth, Li Luyou could only first take care of this great demon king… a little girl proclaiming herself Her Imperial Princess.

- Description from Novelupdates

Roy died during a war against the Evil God Cult, but somehow, he returned back in time to 30 years in the past where he was just a boy who awaken his summoning magic.

Lucian Bowcott only wanted a quiet life. He met up with old friends, made a wish, and died after one drink.Now, he awakens inside a coffin—summoned by the Half-Dead Queen of Atraeum and surrounded by restless souls.Armed with the Death Grimoire, Lucian must embalm corpses, repair brittle bones, and help the dead find peace… before something ancient finds him.As his powers grow, so do the whispers in the dark. If he wants to survive, Lucian must unravel the Queen’s grief, discover why a mortician hasn’t been summoned in over a century, and confront the entities haunting his every step.A/N: It doesn't deal with dungeons, Lucian's system is a magical book, and he slowly unlocks powers to help him with his next assignment. He travels to different places around Atraeum, and in the future, another kingdom.This is a character-driven gothic isekai about an introvert learning that sometimes, peace is more than just embalming a body and preparing it for a funeral. He's more of an undead therapist now