One Piece: Fist of the World - Chapter 36: The Chief Commander Arrives

An ordinary student accidentally traveled into an other universe and became the king of a small kingdom. He had gotten a “Cheating Code” of life and was able to complete something extraordinary. This is the story about a king that was able to conquer continents and leave behind him an ultimate legend that will be recited between every generation to come.

- Description from novelupdates

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.

(Based on LN) Tanya von Degurechaff - once a soldier of the Empire fell in the battle unfairly through that being shameless intervention.**Cursed Being X!**The promised destruction of the soul, and so called last reincarnation is a lie by that being. Tanya - or her new given name Tsuyu Uzumaki found herself in the world of Shinobi - with fox-skinned Godzilla named Kyuubi destroying the village on the day she and her twin brother Naruto were born.Tanya once again curse Being X in her heart because she knows this world is far more dangerous than the last. But that does not stop her from her goal of being able to sit on top and leisurely enjoy life. Therefore, she will rise through the ranks, finding opportunity for herself to finally sit at the throne of Hokage! Or the Konoha Council - eyeing the position similar to Danzo, Koharu and Homura.This is her journey!

Those people killed her grandmother, murdered her younger brother, trampled the people she deeply cared about, and even took her own life.

It was because she trusted her ambitious stepmother and half-sister;

because she mistakenly believed that womanly virtue is to have no talent;

because of her noble status and origin….This is what caused her death.

Buried in river water, Ouyang Nuan, gritted her teeth and spoke, “I, Ouyang Nuan was wronged in death. Even if it takes forever, I will become a devil, and in the next life, will not let you off!”

When she once again opened her eyes, Ouyang Nuan was sent back in time to when she was twelve years old. Around this age, her forehead was scarred, her brother fell into the water, and in three years she will be married…

In this life, she will try to change everything to guard and protect those she cares for from those with treacherous intentions. She will live a glorious life!

- Description from Novelupdates