MTL - The Twelve Zodiac Guardian Gods - Chapter 320 Heavenly Emperor (below)

Perry Z has a Magical Destiny.Born to a Magical Fantasy Princess and a nine-to-five Supervillain, Perry's never felt...adequate. He's completely magically dull, and without a scrap of superpowers.When The System boots, he's forced to follow in his father's footsteps, but he'd rather take after his mother.Maybe there's a way he can do both...

This novel is also known as The Demons Beside Me

Chen Zhao can summon demons and see Death.

“Beelzebub, use your Gluttony ability to treat this patient’s anorexia.”

“Raymond, this old man wants to regain his manly function. You know what I mean.”

- Description from Novelupdates

Dying at a young age after a disappointing life. Mat thought he hit the jackpot when he got reincarnated on a tropical island as a baby. Here, exploring mysterious lands and learning magic are a reality. The world of Elydes is beautiful and magical, wild and savage. While the Guide is impartial to all, people are not. Mat has the lowest starting point possible, and those like him rarely go far. To not let his humble birth define his life, he'll need to find the determination to grow stronger and delve into the mysteries of Elydes.

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.