My Ferocious Tigress Wife - Chapter 865 - : Clear, Hint

Taking place within a world of Measurements―superpowers owned from birth, with most being absolute trash.A world involving numerous secret organisations looking to take advantage of those rare and remarkable few possessing exceptional powers.When there exists Forbidden Knowledge better left unknown.When the discovery of said knowledge results in the inevitable; a world-ending catastrophe.‘Ignorance is bliss.’Fighting against the unrelenting persistence of the one who knows all.Before the tragic fate of the world repeats itself once more.―He must be stopped.

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

I got transmigrated into a game I’ve never seen before.

I thought it was a top-notch RPG and spent 30 years on it.

I retired as a war hero and planned to spend my remaining time leisurely.

But it turns out, it was an academy story?

The King Of Assassins was a monster that reigned over the world of hitmen for long years. He was the absolute peak that no other being could reach. His name reached the ears of every powerhouse in the world and sent shivers through every human.

Yet, his legend came to an end suddenly when he died in unknown circumstances.

However, instead of disappearing forever, he was given another chance in another world by the goddess of reincarnation. It was the world of an old book that he read back in the time. A world where everything was possible, where humans could reach new heights that were impossible in his old life.

But, this place didn't seem to be normal as it carried a huge surprise that will make his journey seem all the more interesting.

The Goddess of reincarnation wasn't as holy as anyone would think. She was nothing but a twisted being who found a toy to play with. The goddess manipulated the world that he was going to and changed all the heroines into these twisted beings that fit her character. They were all now harboring this unhealthy obsession toward him and trying with all their powers to take him away for themselves.