Levelling Up, I Became The strongest Dragon Elementalist - Chapter 16: Thoughts At Night

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

Amakawa Haruto died before he’d the chance to reunite with his childhood friend who disappeared five years ago. Rio, a young boy living in the slums seeks revenge for his mother who was murdered in cold blood in front of him when he was only five years of age.

There exists the earth many knows of and there exists an alternate world. Two people, each with their own backgrounds and values. For odd reasons, the memories and personality of Haruto, one who should have died resurrects in Rio’s body. As the two are confused over their memories and personality fusing together, Rio (Haruto) decides to live in this new world.

Along with Haruto’s memories, Rio awakens an unknown but special power. If he’s to use it, it looks as if he can live a better life, but before that, Rio encountered a kidnapping which results in involving the two princesses of the Bertam Kingdom.

After saving the princesses, Rio is given a scholarship to attend the Royal Academy, a school for the rich and powerful. His background being a poor orphan who once lived in the slums, the school full of nobles was rather a detestable place to stay at.

This is a story of a man named Kim Sae-Jin, who one day, inexplicably wakes up as a Monster. Follow him and his perilous journey to get his life back as a Human, all the while growing even more versatile as a Monster in the process. This should be… complicated, somewhat.

Project BIOHUMAN was supposed to be a quiet project that tested to see if they could create superhuman beings. The Creator, Dr. Vang Chang created the Numbers, ten individuals who took the BIOHUMAN serum and came out different.

Countries caught wind of this and demanded the Creator to disperse the serum to strengthen the humans. The BIOHUMAN serum was shot into the sky and dispersed all over the world. Little did anyone know, it changed Earth and everything living on it. Plants, animals and humans were genetically changed forever.

25 years later, the Creator's son, Lee Seng Chang is a high school student without any Biohuman powers. The serum had given him almost no Dark Matter and only increased his overall human abilities to a super-Biohuman level. Even with that, the power standing only made him seen as the weakest amongst everyone.

Picked on because of his powerless status, Lee Seng was left by all of his friends and labeled powerless. He desperately tries to keep going with a smile on his face. Lee Seng one day gets an option from a man with a Fox mask.

“Awaken your power but at a huge price.”

Lee Seng takes the deal and watches as the world he knew quickly changes and isn't what it seems. Put under the pressures of his Father's status and his new profound power and changes, Lee Seng battles the demons within him and the unknown coming for him.