The Black Beast’s Useless Concubine - Chapter 8

Aomori, who has a monster-fighting system, came to the world of One-Punch Man and gained the ability to enter various instances.

Therefore, “Founder of the Hero Association”, “NO. “And other titles fell on him one after another.

Comprehensive flow, the main world One Punch Man.

Completed dungeons so far: Pokémon – Demon Slayer – Sword – Pokémon – Digimon – Spell Return – Yokai Comprehensive World (Girls that Noragami Inuyasha can see, etc.) – Pokémon – One Piece-re0-Dragon Ball wait.

- Description from novelbuddy

The youngest Wiseman of the continent, Chu Tian, has traveled 30,000 years back in time to the age of antiquity due to an accident.

This is a prosperous era. Rare herbs, minerals, treasure relics and monsters can be easily found throughout the land.

However, this is also an undeveloped era. Communications, traffic, martial arts and technology are in its early stage of development. Prosperous cities lack lighting while its citizens are uneducated.

Our decisive MC using his future knowledge creates Magic powered light bulbs, magic powered telephones, magic powered cannons, magic powered computers, artificial intelligence, psyche internet. 30,000 years worth of knowledge allows him to create miracles and shine brightly in this era. Allowing him to conquer the land and sit firmly on the throne of the 10 realms.

- Description from Novelupdates

A girl who calls herself a demon appeared before a timid student named Fumio Kijima. The girl claims to be a campaign girl from the demon world and she gives him the ability to “summon a room” from nothing but thin air.

At first he doesn’t abuse his power and uses it as a convenient ability in his every day life. But one day he is bullied by his classmates under a false pretext and is made to suffer. In the past he would have wallowed in misery and cried himself to sleep, but now he had a power to call upon.

“I will make them regret it!”

Using his powers to summon his “room”, he begins his era of confinement and brainwashing to achieve his goals.

When low-level healer Elias Vale stumbles upon a cursed cocoon in a forgotten ruin, the last thing he expects is to hatch the reborn soul of the Demon Queen Revantra—in the form of a scared little girl.To save her from divine execution, she binds herself to him through an ancient soul pact, fusing their fates. Now, Elias is stuck raising the former destroyer of worlds—who can barely tie her shoes, but occasionally melts furniture when she pouts.What starts as reluctant guardianship soon spirals into something far more dangerous. As Rhea (her new alias) grows stronger, older, and far too attached, Elias must keep her identity hidden from zealous church inquisitors, ambitious heroes, and the remnants of her own loyal followers—some of whom want her dead... again.But the longer he protects her, the deeper the bond grows—and the harder it becomes to tell who’s really taming who.Because the world once burned beneath her wings……and this time, she’s not letting him go.