This is really not mechanical ascension - Chapter 444 - 236: Internal Intrigue

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.

God gave me one more chance and finally came back after four hundred years.

As soon as I realized I returned, I decided that ‘no one should have pride.’

My goal was to destroy the country. So, I grew up with a genius prince who lived in hiding before returning.
He took up the empire for me and I left him for him to achieve his goal.

‘I came to pick you up Charlize Ronan.’ Dylan, who became a perfect tyrant after a few years, found me after searching all over the continent.

‘Why did you flee and run away?’

Layland Kleinhaus (17) suffers from hypogonadism that makes him less “manly” on top of having a girly face. He is bullied because of it, but he always remains strong ... At least, until he can't bear the betrayals and sufferings anymore.

Filled with rage, indignation, and the lust for blood, he decided to end the life of his tormentors along with the bystanders before taking his own life.

Alas, in the middle of his deed, a mysterious being intervenes the act by summoning him and the rest of the bastards he is killing to another world. He curses his bad luck for not being able to fulfill his revenge because of it, but much to his surprise, there is something much better than having his revenge waiting for him.

“Layland... Be a Demon King.”

Thus, his journey of becoming the unparalleled Demon King begins.

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Those who know me are already in the know of my “condition”—minor dyslexia. So, if you find any misspell or 'wtf does this even mean' words, I hope you can pardon me from the insult, and notify me instead.

A prince sent into exile, without the means to fight back.