Naruto: Reincarnated as Sasuke Uchiha with Perfect Talents. - Chapter 570: Another Strange Person

Three Days of Happiness is a novel by Sugaru Miaki, also known as Fafoo. It’s a rewritten version of the story originally posted to 2ch.

The premise of the story revolves around a shop where one can sell away the remaining years of their life, and the consequences of doing so.

“I Say A Little Prayer” is a short related story which was posted along with the novel’s release. It spoils some things about the main story, but nothing major.

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

Like most candidates, Zlatan's dream was a simple one. To pass the hunter's test, join a guild, hunt monsters and reach the A-class.Eventually, as he dreamed of, he achieved it hundreds of years later. Having sacrificed more than he could take in, using the most unthinkable and brutal measures, he became an S-class Hunter instead.Obtaining the Copper Flame back then after the Aura Awakening Ritual, that was his greatest flaw. Taking a span of 80 years to reach a D-class. Still, Zlatan Elmore became the most powerful hunter to exist.Falling on the battlefield against a Two-horned Dragon, he suddenly awoke as his 30 year old self. Given another chance at life, he didn't only have his memories but he's also given a Blank Scroll. This mysterious scroll doesn't only speak, its omniscient!

A lonely soul, which was placed under the care of the Lord Protector’s Manor, ended up having her lover stolen by the family’s eldest daughter and dying tragically the day before her wedding.

Somehow, she was reborn in the family as their 14-year-old first wife’s daughter, Ning Xueyan, with a startlingly familiar face.

Step by step, she will ruthlessly scheme to seek revenge as well as uncover the mystery of her tragic death.

Her former fiancee, the flirty crown prince and the bloodthirsty prince, will now bear witness to a vengeful Ning Xueyan becoming the peerless lady of her generation…

- Description from Novelupdates