Kyoukai Senjou no Horizon – Girls Talk - Volume 1, Preface

As a precocious child, Lycoris suffers from a strange sense of deja vu. On the day her father told her about her fiancé, she realizes that her fiancé was a character from an otome game she once played in a previous life.

One day, when a novelist woke up from a restless sleep,he realized that he had transformed into his 12-year-old self.

[Ding!][Acquired the Dragon Queen's Legacy][Acquired the Elf Queen's Legacy][You have awakened the Strongest System]“It's real...! Isekai is real!”******Drax is a laid-back, calm and collected highschool student who accidentally loses his life on Earth and, in turn, has his soul is summoned into the body of a baby in another world, one where mana and magic abound.Blessed with a Dragon Legacy, an Elven Legacy and the love of two mummies, Drax decides to enjoy this second life being free and lively freely, not conforming himself to any world system.“The only way to be the freest person is to also be the strongest person,” Queen Freya said to him.And so begins Drax's journey to become the strongest and freest!

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