I Became the Academy's Worst Villain - Chapter 43: Parasites

He is an undead who is devoid of all humanity, he is the one and only supreme overlord, he is a man who has severe mysophobia.

There are many people who try to act cool in front of him, whatever soldier king, assassin, system user, transmigrator, reincarnator, the strong returning, the strong coming down from the mountain, person coming back from the immortal world, reincarnation of the devil king, immortal emperor possessing someone’s body, and so on, all of them do not know what will happen next

- Description from Novelupdates

Mason was a mercenary, until the day he died on a mission after being betrayed by his unit.

Vincent Strider was a gun for hire who made a living by killing whoever it was his clients wanted dead. But during one mission, he died in a fierce gunfight. However, death was not the end for him. Vincent found himself reincarnated in another world, facing a floating interface that flickered before his eyes.[Synchronizing Host!][Military System initializing.]Vincent found out that in this system he received, he can summon soldiers, tanks, aircrafts, and even warships! This is going to be exhilarating.

What is an immortal? They are mortals who have transformed themselves by taking the essence of heaven and earth, shedding their mundane bodies, and gaining the creation of the universe.This is a legend of a lowly beast s*ave who is discontent with his fate and fights against all realms.He knows that only by becoming an immortal can this realm finally catch a breath.