The Fifth emperor of the sea

Prologue

Marinford

Some time in the future

Sengoku POV

Everything was going wrong. It was supposed to show that the marines have power and nobody can mess with the World Government. The execution of Portgas D Ace or as he was born, Gol D Ace, son of the pirate king Gol D Roger. The Whitebeard pirates would come and the marines would crushed them but to his horror, emperor Red Hair Shanks appeared with his whole crew. His son, the newest emperor, Red Hair D Luffy or as he was once known, Monkey D Luffy, also appeared with his whole crew, even when Kuma told everyone that he eliminate them after the youngest Yonko almost kill Kizaru. He also come with his whole Fleet consisting of Buggy, Alvida, Bartolomeo, Mikita, who was a former baroque works, the giants, Dorry and Brogy, Kaku, a former CP9 agent, Law and Booney, who were supernovas like the brat. Also, the empress of Amazon Lily was with her whole crew. She had quit been a Wardlord for some reason and also declared war. The young emperor first invaded Impel down and manage to do a massive break out of many prisoners who were put there more minor crimes, such as stealing food and attacking corrupted marines. There were some who even talk against the Celestial Dragons when they kidnapped their families. The brat even free Jimbei and the Fishman was pissed off

"Sengoku, I will give you this only chance to free my brother" said the young emperor "if not, this will be a bloody war, one that you will send many of this marines in bodybags to their families. So, let's do this the easy way, free Ace and we will not remove the head of this ugly creature". The brat then much to Sengoku's horror, grabbed a badly beaten Celestian Dragon. The brat took his sword out and put it on the World Noble's neck, who was trying to curse him but his mouth was sealed shut with tape

"Gurararara!. Good job, brat" said Whitebeard laughing "now, be a good boy, Sengoku and give us my son back"

"Or do you prefer a full war?" Red Hair Shanks ask in anger, unleashing his conqueror's haki. Sengoku clenched his fists in anger but before he could say anything, Akainu decided that he didn't give a fuck about the World Noble's life and send a magma punch towards the oldest of the emperor's but his commander, Marco, stop the attack

"Damnit" he heard Garp cursed. Instantly, Red Hair D Luffy beheaded the World Noble, as a clear sign the marines attack first and started the war

"AKAINU!!!!!!" Sengoku screamed "WHAT THE FUCK IS WRONG WITH YOU!!!!"

"Pirates must die" he just said "they are scum!" But he was interrupted by a blast of conqueror's Haki, that make him fall to his knees

"Shut the fuck up, you murderous magma dog" said the youngest emperor "guess that it's time to erase the marines, what do you think Sabo?"

"I agree" said a blond boy, who make his heart almost gave out. It was the second commander of the revolutionaries!!! "What do you say Ace?"

"I agree" he said as Sengoku heard the sea stones cuffs fall down. When he look, he froze as he saw that one of the guards have free him and the other was a wax figure

"Sorry, fleet admiral" he said "just following orders". When he lift his head, he recognized him instantly. It was Galdino, another former member of the Baroque works and now a member of the fleet of Red Hair D Luffy "Hope you understand". Both fire fist Ace and Galdino jumped away before he could do anything.

"Garp!" Said Sengoku "why didn't you stop them!"

"Why did you send that mad dog to Dawn island?" He asked instead. Sengoku froze at that question "you send him to kill my grandsons, didn't you?. After everything I done for the marines, you send that mad bastard to murder my grandchildren.  For the respect I have for you, I will not fight with them but don't expect me to fight against them either. You dig your own grave, old friend". Sengoku understood Garp said friend with hatred. As he look around, it was a total carnage, he wonders how the hell that brat go so powerful?. He went from a damn rookie to an emperor in just a few months of sailing, not to mention he conquer the East Blue as well.

AN: You may be asking how that hell is Luffy a Yonko?. Well, that will be explain in a future chapter

AN2: How does he have a fleet?. Well, again, in a future chapter

AN3: Why would Luffy kidnapped and kill a Celestian Dragon?. While I know Luffy will never do something like that. He did punch one, knowing very well the consequences but I doubt he would he kidnapped one and later kill one. Would the marines exchange Ace for a World Noble?. That I wouldn't know.

AN3: Would Akainu attack like that, while didn't given a damn about the World Noble?. I would say maybe,  considering he murder a marine and kill anyone in his path, like the Ohara civilians. He would probably kill the World Noble and blame the murder on the pirates. All for his absolute justice crap. If I am wrong, remember this is a fanfiction and everything is valid, like making poor Luffy the son of Big Mom or one of her children. There are even stories where Luffy is a marine and to be honest, I just can't stomach that. It's just too weird.

AN4: I just finished watching one piece episode 1079 and waiting for the next one that is coming next Sunday if I am not mistaken, so I know Luffy's devil fruit true name is the Human Human devil fruit mythical zoan: model Sun God Nika and about gear 5 (I would say it's technically a spoiler but I know that everyone probably already know it, considering there are fanfictions with the name of the fruit as it's title and others just don't give a damn and just mention it)

AN5: Luffy will not be the same as the canon. He is more aggressive for what Akainu did and he hates marines, like he would kill them if they mess with his crew or hurt innocent civilians. Again, there are fanfictions were Luffy kills marines as revenge or because he acts like a pirate

AN6: Like the summary says, he and his siblings were rescue by Shanks. Also, he trained them for seven years. Also, Luffy is his son and his mother is a female Dragon, so Garp had a daughter instead of a son here. I read a fanfiction with this idea and there are probably more. We don't know Shanks last name, they just called him Red Hair Shanks because of his hair, so Luffy will have red hair instead of black in this story and I will change his name from Monkey D Luffy to Red Hair D Luffy or he will change his own name

One piece and all his characters and places belongs to Eiichiro Oda