School Beauty's Invincible Martial Expert - Chapter 599 - 601: Crawling In

One of the six people called heroes, Raid, fought alone against the Devil, and ended up dead.

After meeting with a suspicious god, he woke up again and found out he has born again as a baby.

Moreover, as a daughter of his former companions.

In order to regain his former power, Raid/Nicole has to go through a life of hardships to reach the ideal he aims for.

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

Cassian Ven Dyke, the bastard son of a powerful ducal family, grew up in the slums of Veldora under the care of his father figure, sword master Russel. When Russel passed away, Cassian was left with only a silver necklace as his inheritance. After putting it on, Cassian was attacked by three psychotic thugs who tortured him in an attempt to steal the necklace. Refusing to give in, Cassian was ultimately stabbed through the heart with the very same necklace. Instead of dying, he mysteriously vanished as the necklace lodged itself in his heart. Just before disappearing, he heard an eerie message echo in his mind:[True mana detected. Origin: Human...][Human detected. Compatibility with system: Confirmed.]

I thought I would live a better life in my second lifetime. Unbelievably, I’ve reincarnated into a slime that rolls around on the ground. Anyway, this is my precious new life, so I must work hard.