From Overlord To Multiverse. - Chapter 4: First Kill, Profession lvl3

Xue Xi is forced to fall in love at first sight with this dangerous man on their first meeting. With death being the only other option, she makes the first move:

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.

After being reborn in a sci-fi ABO world, Xi Wei became the newly born son of the Imperial King. He thought, as the emperor’s son he could live a carefree and imposing life, but unexpectedly the First Prince is actually an omega? What the hell is an Omega?

There was an alpha who was born on the same day as the First Prince Xi Wei, the two children grew up together. When Xi Wei looked at the blonde child next door, he always felt that the boy was not pleasing to the eye, so as a child Xi Wei bullied him.

Until many years later …

Looking at the man standing in front of him who was one head taller than him, Xi Wei was dumbfounded.

–He tried to get out of the way, but eventually still fell into his childhood sweetheart’s clutches.

- Description from Novelupdates

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.