Weapons of Mass Destruction - Chapter 38: "Meow"

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

Eli was transmigrated to a world of magic and became immortal.

He had endless life and could never die.

“Huh? I’m talentless? Then, I’ll just train for as long as I need, even if it takes 1000 years. That should be enough for me to become strong.”

“The skill is hard to learn? Then, I’ll take a few dozens of years to research it. There’s no way it’s that hard, right?”

“What? I can sacrifice my life force to gain spirit power? That’s a bargain!”

“The enemy is here? Hell, I’ll just hide for 10000 years. Let’s see if he can outlive me. I’ll come out once he’s dead.”

This is the story of an immortal who first struggled to live in the world of magic until he became strong enough to slaughter endless worlds.

Venshiro, a young ronin bound to the Black Vein Blade, is hunted by clans who would kill for the curse he carries. Every time he draws the sword, it takes something from him—his memories, his soul. But the blade remembers everything.And now, it wants more.

“Shit, is this really how I turn out?!”In the time of war he was known as the Body Flicker, Forbidden Magic Maker, and the Golden Blur.Arthur Vaelthorne.He had so many titles that it was unsurprising that the empire was the side that won the war, all because he had participated in it.A man that had the potential to become the strongest, rivaling the old powers, and the talent to back it up....Only ended up as a hidden boss in a popular game, meeting his end at the hands at one of his own students.A powerful hidden boss, unfortunately he had the fate of any other boss: Beaten by the protagonist.Now, with a second chance and the memories of one of the game's top players, he has a chance to rewrite his fate.