I'm the Mysterious Leader of the Salvation Organization - Chapter 440:

He died in his first life, as an ordinary human inside an ordinary planet.

In his second life, he swore to live a life of supreme power, and so he did. He reached the apex and exterminated his enemies to oblivion.

Dying, he was reincarnated in a world which could use Chakra. He became The Overlord Of Every Being, Ruler Of 6 Universe.

Unfortunately, he died. Using a mysterious method, he was reincarnated once again inside the world of Tales of Demons and Gods.

Ye Xiao was a superior cultivator in his previous life. The three factions of the realm kill millions of people every time they attempt to seize cultivation resources. Wealthy towns turn to wastelands in just a single night. They cover up their crime with an assertion that the towns were suffering from pestilence and disasters.

They forcibly hold all the resources for cultivation, monopolize all valuable practice materials, and keep outsiders from cultivating so that only their three factions could cultivate in the realm. Ye Xiao declared war against the three factions in retaliation for their actions. He fought alone and ended up dying in vain. However, he is reborn into the mortal body of a 16-year-old boy. He will use the powers he cultivated in his last life and slaughter his way back into the Realm. The story begins!

- Description from Novelupdates

As a successful villainous BOSS, in addition to having ideas and aspirations, one must also keep in mind three points:First, grow sneakily, don't act rashly (once a villain acts rashly, they basically won't survive past three chapters).Second, you're not a good person, so be ruthless (becoming more evil will make you three times stronger, while redemption weakens you by seven times).Third, remember the two points above. The moment you forget them, your end is probably on its way.

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.