World Isekai - Chapter 55: [First Boss]

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

- Description from Novelupdates

The world is a place full of mystery, and many ordinary people live their entire lives without ever glimpsing even one percent of its truth.The fate of one family was destined to be average until one rainy night, when a family member arrived at the newly married couple's door with a child born out of wedlock.Terra was about to undergo an upheaval because... the strongest was born!---------------------This is the story of Kaizer Lunin, a young man born with a special ability that causes him to suffer from mild antisocial personality disorder.A brush with life and death awakens this power fully, turning him into one of the strongest Espers in the world!However, this also thrusts him into the hidden parts of the world, where secret societies, powerful factions, and the government clash in their bid to claim the empty title of 'strongest Esper'—a void left by a certain someone.And maybe, if he doesn’t die prematurely, Kaizer has a shot at that title himself!

In the original lines of the novel, I was a villainess—used as a political tool by my father and older brother—who ended up dying at the hands of my future husband.

Miguel transmigrated into the Wild Beast World in the body of a useless teen with the same name as himself after he was betrayed by his disciple, the Harem Emperor, for a knowledge and universal secret that he recently uncovered.In the Wild Beast World, humans could contract Wild Beasts through their Summoning Grimoire, a mysterious book that fated individuals can awaken at the age of 18.In this world of summons and beasts, Miguel awakened with the Beauty Sign-In System, which allowed him to contract legendary beauties as long as he signed in at a specific location.On his first sign-in, he received the Holy Daughter of the Red Family, the Fiery Empress of Legend.Using the Wild Beast World and the Sign-in System as a starting point, Miguel swore to return to the Immortal Cultivation World and settle scores with the Harem Emperor once and for all.Follow Miguel's journey as he reaches for the apex, becoming a legendary figure in all worlds.