The System Mistook Me for a Cat - Chapter 17: Theme

When a person dies, they either die light as a feather (aka unimportant) or heavy as Mt. Tai (aka very important).

I was a failed experiment

A young boy genius, Suo Jia, is a water mage who dreams of being a warrior travelling the great and dangerous trade routes to find his lost father that set off on them before Suo Jia was born. Having to look after his sick mother, Suo Jia manages to find a way to solve all their problems, as well as make a name for himself. He gathers nobility, vast wealth, items of great power, knowledge lost to the ages, and exceptionally talented females around him as he plots and plans – preparing to set off on an epic journey that will go down in history as a new legend. However, will others that depend on his powers so much be willing to let him go on such a dangerous journey so easily?

- Description from Novelupdates

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.