The Undying Immortal System - Chapter 341: Life 79, Age 30, Martial Sovereign Peak

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

In a world where dungeons were an essential part of it, Rein was trying to conquer as many as possible. They were the key to gain powers in the fastest possible way. So, to reach his full potential and to become the strongest, he became a great dungeon conqueror.With his trusty friends and lovers, he was definitely going to reach the peak alongside everyone. Join Rein and see how he went from strong to stronger and then the strongest.__________________1. The harem would not be too large(I'm not sure how many but probably just 4-5 main and few other here and there). All the girls would be getting their time and story.2. The story is starting when the MC is in the middle of his growth stage and not at the very beginning. But his beginning will be mentioned in the story in some form.3. I don't think I need to mention this, but obviously it will not have any NTR, rape or that kind of stuff. It is actually quite a wholesome story focusing mainly on adventure, action and bit of romance and slice of life.

Zhuang Feng is in his last year of high school, and he’s just moved to the city. He lives with his good-for-nothing cousin, who’s always on business trips falling for get-rich-quick scams, and his Saozi (sister-in-law), who tries to make his life miserable as much as possible. There’s one upside, though; she. is. freaking. hot. But one day, he found a piece of her underwear in the bathroom…. And unfolded a series of events that will turn his life upside down.

- Description from Novelupdates