Infernal Hero - Chapter 2 Sons of Hell

This is the story of Kir, who has to thwart the will of Heaven, Hell, and his parents in order to survive, protect the people he loves, and achieve happiness.He just has to make it through life at a magical academy, avoid dying, and survive to find his birth mother, the lost Daughter of Heaven. Or be forced to take his place at the side of his father, a Duke of Hell bent on destroying the way things are.It's a lot to handle for a quiet, brooding angel boy.Fortunately, he has company. A succubus, a foxkin girl, and a half-angel boy to start. And Kir has his own secret: this isn't his first go at life.

Hey? Why is there a HP Bar and a Title above your head? Why do you know magic? Hey, why are there people slashing their swords at me!? What’s wrong with this world? Why is it so much like an RPG!? HEY!!

Chu Xuan transmigrated to a fantasy world and became the young master of a powerful family. He was rebuked for misbehaving just because he sneezed during a banquet. As punishment, he was banished from the ancestral mansion and was relocated to a remote residence.

He did not mind the punishment at all. He just needed a spot that could allow him to be a shut-in. With the system that would allow him to grow stronger by being a shut-in, the longer he stayed indoors, the more powerful he became.

After being a shut-in for a day, he was rewarded with the Indestructible Body Technique.

After being a shut-in for a month, he was rewarded with the Immovable Mountain Technique.

After being a shut-in for a year, he was rewarded with the Yuxu Celestial Scripture and 100 years of cultivation.

After being a shut-in for 10 years, he was rewarded with the Chaotic Indestructible Body and the Bell of Chaos.

…

Chu Xuan declared, “No one can make me leave my home. I like being a shut-in!”

A Federation Colonel with abnormal thoughts was locked in a dark room and met a little looney.

“Your whole body emits a scent that I dread (covet) and fear (desire).”

A frigid Colonel X little looney roommate: A sweet story of interstellar travel

- Description from Novelupdates