MTL - Co-renting Immortal Doctor - Chapter 189 Tyrant, let's be friends (six more!)

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.

Aaron, a wildlife biologist, became a military strategist right after a global war between nations began.He never wanted to participate in the war but he had to, because he wanted to continue his studies on endangered species the moment the war was over, but to his surprise, everyone in his unit were killed, including him, and the next thing he knew, Aaron woke up in the body of a young noble having a similar name to his.However, he also noticed he had awoken in a world different from Earth.In this world, demonic beasts ran rampart with only one thought in mind, causing them to feed on anyone they see, be it humans, elves or even magical beasts as well.During his first encounter with a magical beast, Aaron awakened a system which allowed him to bond with magical beasts and to obtain terrifying abilities from these bloodcurdling magical beasts, so he used his experience as a wildlife biologist to help make it easier for him to bond with these beasts.However, Aaron also noticed he could evolve these beasts if their loyalty towards him had reached a certain level, so he vowed in his heart to grow strong enough to protect those he cared about in this world with the hope of living a happy, peaceful life where he'll be able to focus fully on his passion as a wildlife biologist.

Collection of short stories.

- Description from Novelupdates

The world was never the same after that day.Humanity learned that they weren't alone in the universe, but that wasn't something they had the time to worry about.Their realization was accompanied by catastrophe.Creatures beyond their wildest imaginations poured down from the sky and appeared from the earth. They slaughtered humans as if it was their singular purpose, driving them to the brink of extinction.The people of the world did everything in their power, developing unique traits and technologies to create a united front their enemies couldn't penetrate.They secured victories and repopulated, feeling as if they stood a chance against the foreign invaders.They fought and they fought, doing everything they possibly could to ensure their survival.Until the Great Calamities appeared.In front of them, humanity was nothing regardless of its efforts.One by one, the worlds were turned into piles of rubble in between the cracks of their teeth. Civilization was torn apart, and the evolved humans living within could do nothing to stop its collapse.Humanity itself was left extinct, and in the end, only a single man was left alive amidst the chaos.Why?For what reason were they punished so?Nobody knew why the attacks began in the first place.He looked into the distance at the memories of the past and firmed his resolve.“It can only be me.”He knew of a miracle that could return him to the place of those memories.He knew of a way to make the wheels of time spin in reverse.And using it, he alone would save humanity from its doomed fate.That was his sacred duty as its final survivor.