Perfect Revenge : CEO's Lovely Mistress - Chapter 36

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.

He holds a god-level sign-in system in his hand, punches the goose factory, and steps on the pig factory. Do you think there is no good game?
First feed you two mouthfuls of tainted milk powder, and then send you the legend of the dragon and the Hearthstone gold cartoon for free.
What? Still not satisfied? League of Kings out-of-print skin, give away!
Satisfied? Tch, this is just the beginning…

- Description from novelbuddy

This is a story about the protagonist getting the system, going crazy in the biochemical apocalypse, producing aircraft and tanks, destroying zombies, saving good people and killing bad people.

- Description from novelbuddy

In a post-apocalyptic fantasy world layered into multiple realms, humanity faces extinction due to their endangerment of the main realm. Forced to merge all realms back into one, a deity grants humans a leveling system to empower them, lest they become extinct when facing the mythical creatures. Noah, our protagonist, embraces the role of a monster tamer, trading his humanity for strength and eventually transforming into a monster himself. As Noah struggles with his evolving identity, he must navigate a world where the line between human and monster becomes increasingly blurred.