Adding Friends Can Make Me Stronger - Chapter 28 - Your Gray Avatar Will No Longer Flutter

This is the story of a modern sailor who was accidentally reborn as a soldier of the Brazilian Expeditionary Force, and finally became the largest plutocratic family in Brazil by virtue of his foresight.

- Description from novelbuddy

This story is set during the end of the Sui Dynasty, a time where multiple powers struggled for supremacy and power.

Into the fray enters two orphans Kou Zhong and Xu Ziling; these two youths by many chances and luck obtain ‘The Secret to Long Life’ allowing the two to obtain profound martial abilities and a chance to rise to the top in this age of turmoil.

Upon waking, Wang Shan finds himself in Room 888, the most luxurious accommodation in Cloud City, typically reserved for the wealthiest. Despite his complaints about the “”subpar”” room, five stunning women are waiting to inform him of his first-place assurance in an upcoming test due to his powerful father’s influence.A stranger to this world from the 21st century, Wang Shan learns that martial prowess is paramount, categorized into nine realms. Today, he must take the One-star Cultivator test, despite his supposed lack of innate talent. His father’s status as the ruler and a formidable Two-star Expert guarantees his victory, but the arrival of the gifted Zhang Bao poses a deadly challenge.As Wang Shan bathes, he hears a voice in his mind: “”System binding, binding successful.”” A powerful trading system allows him to trade anything he touches, enabling him to instantly advance his cultivation. With newfound power, Wang Shan contemplates his next move. Will he overcome the threats and rise to greatness with the help of his mysterious system?

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.