I am that male friend in the harem story - Chapter 13: Ishigami is ready to become a sacrifice

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.

The rivers and lakes carry wine with swords, the waist is slender and the palm is light.

The young man carried a long knife on his shoulder, and hung wine on his waist, striding forward, but the rivers and lakes in his heart were vaguely visible.

Turning a page in the book of troubled times, the rivers and lakes have been raining nightly for decades.

Looking back suddenly, the world has been shattered.

- Description from novelbuddy

I dedicated 10 years of my life, focusing solely on regression.[Authority: Death Regression has naturally been nullified.