MTL - This Ninja is Obviously Not Strong, But He Kills Too Much - Chapter 587 This man, I cover it!

Sing the story, bard, of the Firebrand. He, the youth who saved Morcaster from ruin. He, the warrior who defeated an empire. He, the archmage who crossed the Netherworld...The tale of Martel the mage, from his humble beginnings as a hapless novice at a magic school. Slow, character-focused and light-hearted progression fantasy. Updates daily.

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.

In novels with a stud there is always a Senior Martial Brother like this:

In the early stages of the novel, his innate talent is high, his cultivation is good, his appearance is handsome, and he has an intelligent, cute younger Martial Sister as a fiancée.

In the middle stages of the novel, he is caught unprepared and defeated by a young disciple (the protagonist) in the sect who’s hardly remarkable at all. From then on, he falls from his godly altar and loses his brilliance. Even his young Martial Sister leaves him for someone else.

In the late stages of the novel, he continues to turn dark, going down the Demonic Path and becoming the major villainous boss. However, the protagonist still ruthlessly defeats him and his soul is eternally sealed.

Once Qin Mo opened his eyes, he discovered that he had become this Senior Martial Brother.

- Description from Novelupdates

A Deadly Secret, also translated as Requiem of Ling Sing and Secret of the Linked Cities, is a wuxia novel by Jin Yong (Louis Cha). It was first published in the magazine Southeast Asia Weekly (東南亞周刊) and the Hong Kong newspaper Ming Pao in 1963. Its original Chinese title was Su Xin Jian before Jin Yong changed it to Lian Cheng Jue. The story revolves around the adventures of the protagonist Di Yun, an ordinary young peasant, who is imprisoned after being framed. In his quest for vengeance, he accidentally acquires the Liancheng Swordplay manual (連城劍谱), an ancient artifact not only prized for the skills detailed inside, but also for containing a secret leading to a treasure.