1 Stoneheart D. Caesar

A guy was reincarnated in the world of One Piece with The Broken System.

This was only the first of many worlds, and this world had several main quests that he had to complete or he would lose his life.

There were several main quests that the system had given him are -

1. Reach 10 Billion Bounty

2. Find One Piece

3. Destroy World Government and Celestial Dragons

4. Become Emperor of the World

Time Limit - 5 Years , failure will lead to death.

The main quest would begin when he would turn 18.

He had several abilities that would help him achieve the main quest -

Abilities -

Steal - Can steal any and all abilities of anyone the user kills

Command - Can command anyone weaker than the user making them your follower

Drain - Can take the lifeforce of your enemies and convert it to experience leveling yourself up

Seduction - Is naturally extremely seductive to anyone weaker than him, can also gain experience and abilities of anyone he has sexual intercourse with.

He was reborn as the son of Silvers Rayleigh and Stoneheart D. Carmen.

Rayleigh had met Carmen during his journey with Roger and had a son with her, he left them behind as he thought that would be safer for them

After the execution of Roger and the disbanding of Roger Pirates , before Rayleigh could get back to his family the Marines had tracked them down and intended to hold his wife and kid as hostage.

Carmen who knew this did not want to become the reason the Marines could get to Rayleigh so she resisted till the end while she hid her son away so the marines couldn't find him.

She ended up being killed by the marines as they could not take her alive as Rayleigh saw the dead body of his wife and his son was hidden away with someone else.

He was infuriated and went after the marines who took his wife's life and slaughtered them all but there was only so much he could do single handedly against the world government while also protecting a kid as the world government was on a manhunt against him and the other roger pirates after the execution of Gol. D. Roger.

The Roger pirates and also disbanded so he could do nothing and thus decided to take his son away and remain hidden from the World Government atleast until his son was strong enough to protect himself.

He decided to name his son after his mother's name so her memory could live on forever , naming him Stoneheart D. Caesar.

He resided on the islands that would be called Amazon Lily in a previous timeline and named it Carmen Islands after his wife.

As Caesar was someone from our world he saw the system notification and the main quest that would begin at 18.

While still being a transmigrator he was greatly affected by the death of his mother in this new world and would still go against the world government and the celestial dragons even if the system didn't tell him to.

He trained hard with Rayleigh as his life depended on him achieving the System Quest.

He had great natural talent and thanks to the system that allowed him to steal abilities and level up by killing he became strong very quick as he unlocked Conqueror's Haki at age 10 and started learning Armament and Observation Haki at age 15.

By the time he reached 17 he had leveled up to Level 30 , all three of his haki had reached Master Stage while his sword skill had already reached Legend Stage as he was trained by his dad.

During this time had gone out on adventure fighting pirates and marines and getting real combat experience when he encountered Boa Hancock and her sisters escaping Mariejois and protected them from the marines and took them back to Carmen Islands.

Part of the reason he helped them was because of his hatred towards the World Government and especially the Celestial Dragons who sat high and mighty and did what they please without the consideration of others.

Boa Hancock and her sisters were shocked to see someone help them knowing it would make them the enemy of the World Government for helping slaves and came to respect him and his father as they made themselves home on Carmen Islands.

He helped the other slaves escape too as they formed the Kuja Tribe on Carmen Islands though in this timeline their principles and beliefs were different as they regarded Caesar as their savior while Boa Hancock led them to a better life with him.

During this time he had also fought with Issho, he was very strong but he was far behind the Admiral level yet so after a long and arduous fight that shocked the entire world he managed to kill him and take his devil fruit, the Zushi Zushi no Mi or the Gravity Fruit.

—

"Well son, you have finally turned 18, are you going to leave?" asked Rayleigh as he saw his son, he was a tall and huge man with long brown hair.

"Of course, I need to do this, but aren't you going to tell me more about One Piece?" asked Caesar.

"I would but if you want to use One Piece, you must find it yourself, that is the condition of One Piece, if I tell you anything about it you will never be able to use it" said Rayleigh mysteriously as he laughed.

"You gotta give me something old man" said Caesar.

"All I can tell you is you need to find poneglyphs and you need someone who can read them" said Rayleigh as he handed him a picture.

"Nico Robin, part of the Warlord Crocodile's crew , currently in Alabasta huh?" said Caesar as he looked at the photo and the document.

"That's right, you need to get her on board if you want to find one piece, she is the only one alive as far as I know who can read poneglyphs," said Rayleigh

"It's better than nothing, I'll be on my way then old man" said Caesar as he walked out.

Rayleigh did not know what drove his son to go against the world government, maybe it was the death of his mother or something else. But regardless, he would support his only son no matter what he wanted to do.

As he walked out towards the port he encountered Boa Hancock who pressed her body against him.

"Are you leaving?" she asked as she twirled her finger on his chest as she looked at him lovingly.

They had essentially grown together as he saved her life and had become extremely close as she fell in love with him.

She was now a Warlord putting Carmen islands under her protection which let the Kuja tribe, Rayleigh, and he lived a peaceful life so far as the marines had no idea they were living there.

"I can't achieve what I want to by just staying here" said Caesar as he held her in his arms and kissed her.

As their lips parted she said," Promise me you won't pick up too many women!"

"Oh well, I can't promise that can I" said Caesar as he teased her causing the latter to punch his chest lightly as a joke.

"Can't I come with you?" she asked.

"Not now, you need to remain a warlord till I build up a crew and stay on the low, once I come back, we can be together," said Caesar.

Growing up with all of these women wasn't easy as after he saved them and gave them a new life they wanted to thank him and as a result, he was drained continuously until only a husk of his body remained.

He shuddered as he thought about it and left Carmen Islands towards Paradise.