Clan Building System: I'm not the Protagonist?! - Chapter 41: Secrets.

Upon awakening, Su Changkong found himself transmigrated to a world thrown into chaos by war and rampaged by demon monsters, where his martial arts talent was mediocre. However, Su Changkong discovered that as long as his own “life span” increased, his talents and potential could also be “limitlessly” enhanced!Cultivating the Health-preserving Fist technique and practicing the qi of longevity! The path to immortality is littered with corpses, and Su Changkong embarked on a Martial Arts path where he would not perish, even if heaven and earth were to be annihilated!

A mecha otaku is reincarnated into another world as Ernesti Echevalier (Eru). In this world there exist huge humanoid weapons known as Silhouette Knight. Dreaming of piloting those robots, Eru, with childhood friends, Archid Walter and Adeltrud Walter: together they will aim to become a Knight Runner, pilot of Silhoutte Knight.

This is a game that surpasses dimensions.

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.