Story of The Ancient Demon King! - Chapter 73.1: Servants are not teachers…

Carn wakes up from a vivid dream where he spent a thousand years as a gargoyle, guarding a demon lord's tomb.In this dream, he possessed supernatural powers, including the ability to teleport and instantly kill anyone within range who broke eye contact with him. Heroes, saintesses, adventurers, all fell before him.When he returns to his normal life, things take a strange turn. Carn realizes he still has the gargoyle’s powers, and the world he has woken up to seems different.But adjusting to the new reality is not the real issue. Carn brings back something nobody in this world has imagined. Not only he imports his powers to this alternate Earth, but he also carries over his gargoyle instinct and his hobby. He loves snapping human necks.Whether it's ordinary humans, explorers, super soldiers, cyborgs, mutated beasts, monsters, or mysterious entities from other dimensions, Carn eagerly anticipates snapping their necks, one neck at a time...In secret, of course.

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

A mediocre, low-born beggar, he relied on only his firm and indomitable spirit to desperately cultivate but still could not exceed the masses. Then by fortune’s favor, he awakened a long-extinct ancient martial soul. Since that day, he soared like a comet on the path of cultivation. From his humble beginnings as an outsider in the Ling Clan, his name, Ling Xiao, would ring throughout the world.

Kuramoto Daisuke, a freshman in High School was suddenly exposed to someone vanishing in front of him. Turns out he was admitted to a Special Class full of Isekai Heroes that were regularly summoned to Otherworlds since the start of their Middle School. He was told that he was to become their Support to prevent each of the Heroes' fate of dying in the world they were summoned into. Though mediocre, he realized that his ability has a great potential but it needs a lot of hard work on his part.

Unconvinced of being just the Support Character, he vowed to excavate his mediocre ability, all the while supporting the Heroes using it.

And maybe more.