Lonely Attack on the Different World (WN) - Chapter 272

A teenager named Evan Mason was reincarnated into the magical world of Harry Potter and goes to school at Hogwarts!
With only his knowledge of the future and great talent for magic, he takes the path towards the top of the magic world, only to realize that ever step he took, changed everything!

- Description from Novelupdates

In the twenty-seventh year of Hong Guang, the allied forces of seven nations invaded the Great Blue Dynasty.Rifled muskets, mortars, and armored vehicles combined into a steel tide, were ultimately shattered by the Great Blue's armored cavalry.Muscle, magic, firearms, cannons... the new and the old powers continuously collided.In an era of great strife, Li Fei, with the help of a Ten Thousand Blood Bead, gradually became an existence akin to a BOSS:'Is this the extent of your damage? You haven't even taken off one-thousandth of my health.''You don't think this is enough to kill me, do you?''Don't rush, the second phase is up next!'......

Traveling to the Marvel world, Luo Bai found that his luck had improved.With no place to live, Tony offered him a villa.Although he had no abilities, the Ancient One stated that he was more gifted than Doctor Strange and could become the Sorcerer Supreme.Without any magical weapons, he simply picked up an infinite stone while walking.When Thanos came to steal the stones, he didn’t manage to grab any; instead, all the other gems were “gifted” to Luo Bai.They say that magic must be borrowed and repaid? In the end, he became invincible...Disclaimer: This is Translation

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.