PhoenixAsh

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.

My Beast Evolution System

The serpents struck first at a lightning-fast pace as they lashed out with their tails, but Glimmer and Thunder were the first to react to the creatures' attack.

Thunder dodged two of the serpents' attacks and his hooves sparkled as he swiftly countered it with a burst of electricity that made them hiss. However, they also retaliated with a burst of dark energy that sent Thunder skidding backward.

Meanwhile, Glimmer unleashed a huge stream of crimson flames that melted the serpent until there was nothing left of it.

Aaron, Diana, and Aurora tried to get closer to the two beasts that were facing off against Thunder. But Thunder was determined to handle the two of them on his own, so he swiftly squared off against the beasts.

46. Thunder’s Evolution.