One Piece: I am Imu - Chapter 16: The Administration Department arrives in the Capital of Water

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

Due to being reincarnated into a financially struggling noble family, I had to find a way to make money.“Just wait one more day, and the next volume will be out!”“Next week is a hiatus? Are you out of your mind?”“Hurry up and give me the next volume!”“Quickly!”Before I knew it, I was overwhelmed with deadlines instead of romance.

Nyx, Earth's former number one mercenary found himself on the end of his life failing to escape from a powerful criminal mastermind. However, fate seems to have another plan for him when he woke up in a completely different place, a place that he will eventually call home in the new world where strength makes one the biggest boss.[Welcome to the Universal Shop System!][Detected that it is the first-time log-in. Reward: Random Gift Pack (5)][Detected the user entering the Body Tempering Realm. Reward: Infinite Qi System][Opened Random Gift Pack (5). Acquired True Transcendence Body Art (1). Acquired Primordial Nihility Transcendent Qi (1). Acquired Immortal Illusion Art (1). Acquired Grand Desolation Transcendent Body (1). Acquired Extreme Origin Transcendent Soul (1)]With an absurd system as his cheat, follow the young man's journey through the entirety as he gains his position as the one true peerless existence, the sole transcendent above all.

An otaku with a hobby of masturbating was reincarnated as the son of a great mage.

As soon as he was born in this life, he vowed with a goal of embracing women till his death.

That said, when he became 20 years old, the Demon Lord which was sealed by his ancestors revived, and now it is his role to seal it once again.

And that demon lord is sealed in a tower dungeon that is rumored to be impossible to capture.

However, by an unexpected coincidence, he had found out that the Demon Lord is also one of him, a kindred spirit from within,

so he joined her instead and filled several traps in the tower dungeon, and thus they enjoyed a s*x spree with all the women coming over!