Witcher: I Can Extract Everything - Chapter 19

He rose from abjection and achieved eternity in glory.
He embraced the prettiest beauties and killed the strongest opponents.
He was able to shift the clouds into rain and cover the sky with one hand.
He could overrun the entire world and go anywhere as he pleased.
He pacified wars and held the world in awe.
He was matchless in the world.
However, his hair turned white overnight for his beloved woman and he was on the verge of death.
He was surrounded by enemies who were trying to take his life.
He struggled his way to become mighty and fought for everything he cherished.
For this age, he was the only king of the Dark World.
His name was a byword for might.
As a man living in the world, his only ideal was to pursue brilliance.

- Description from Novelupdates

Suzumiya Kaede, a gamer, fell asleep while playing a game all night and when he woke up he found himself in another world, a fantasy world where using magic is possible! Using his knowledge of games, skills, and cheats, Kaede decides to enjoy as much of his new life in a different world through his newly-acquired magic and sword!

The world was consumed by a vile corruption brought from beyond – the sun dimmed, and life as we know it was almost extinguished.And yet it was not the end but merely the beginning.Long after the disaster, a lone survivor awakens with a newfound power to wield the divine flames and many questions about the past. He embarks on a long journey to burn the rot away, discover what's left of the old world and maybe, just maybe, ascend to divinity.