There Will Always Be Protagonists With Delusions of Starting a Harem - Chapter 21

He lived from BC to the Middle Ages, from the Renaissance to the Industrial Revolution, and from Cyberpunk to the Interstellar Age. He has been a king and a prophet, a knight and a nobleman, a versatile artist, a genius inventor…
This is a four-thousand-year human epic——
“To us four thousand years from now:
“Is the world at peace? Is famine extinct? Can people touch the stars? How long is the human lifespan? How far is the boundary of the earth? Human…do you remember us?”
——Excavated from Earth Age Tenth Century BC, Solomon Prayer Book.

- Description from novelbuddy

Death, Depression, Poverty, Love issues – all things that a 27-year no-name writer faces.

Octavius, misled by friends, embarks on a quest to clear his father's name, ultimately facing a tragic end with his sister.Their journey results in devastating loss, leaving him powerless and yearning for revenge against those who harmed his family. Spirits offer him a chance to reincarnate, but he refuses, saying;“What’s the point of a new life if I keep running from my problems”The entities are taken aback by his unwavering decision, having never encountered a spirit who refuses to escape their troubled past. They warn him about the evil being that now resides in his old body, but that only motivates him. He believed In the saying - to defeat a monster, you have to be twice as monstrous.Embracing his fate as The Phantom's Gambit, they traverse the shadowy path of retribution, their identities blur, secrets unravel, and the line between savior and monster fades.This is a tale of darkness and redemption, where justice is a blade, and revenge is the only way forward.

This is the story of a modern sailor who was accidentally reborn as a soldier of the Brazilian Expeditionary Force, and finally became the largest plutocratic family in Brazil by virtue of his foresight.

- Description from novelbuddy