Another purpose

Training Montage

"What gives you the right to decide things like that Rayleigh!" Yelled the beautiful Boa Hancock. Itachi was watching the exchange between her and Rayleigh, the Dark King.

"Well Hancock if you truly want Luffy to become strong you cannot pamper him, it's unbecoming of a man who wishes to become the Pirate King," replied Rayleigh in a stern voice.

"Beside, do you want a early death for him?" The Amazon Empress quickly shuttled her after that statement. If course she didn't want her "beloved" to die. So she kindly put her pride aside and let Luffy, and Itachi trained with Rayleigh on a island in her territory.

In the end Hancock conceded that Itachi could stay but decided to threaten both Rayleigh and Itachi so as to have the final say in the matter.

"If either of you mess up Luffy's training or eat his food I'll make sure that you both suffer." Hancock says with a glare which would of made any lesser men crumble and wilt but it simply made the old man laugh and the young Uchiha just had deadpanned expression.

The Kuja all cheered for Luffy as they boarded their ship to depart but still sent glares at Itachi which of course were ignored as the raven haired man had just spotted a Sea King break the surface of the ocean a few hundred metres off the island. After some more farewells. All of which were directed at Luffy. The Kuja departed leaving the three men alone on the island.

"Well come on you two, we're burning daylight" Rayleigh says as he turns and walks off into the jungle. Luffy turns and follows him after mumbling something about protecting everyone. Itachi had a hand on Luffy's shoulder and gave him a reassuring smile. The captain replied with a smile of his own.

Sighing and sparing one last look at the ocean, Itachi turns and walks after Rayleigh and Luffy.

'I'll protect him, Ace.' He thought as they enter the jungle.

MONTHS LATER

The sounds of combat could be heard from anywhere on the island and the presence of the combatants was enough to cause the weakest of animals to black out or flee. A bruised and cut Itachi flew backwards out of the bushes, he back flipped and managed to right himself and land on his feet. After a few seconds catching his breath he began to weave hand seals faster than most could make out, holding the Tiger seal with one hand, he took a deep breath.

"Fire Style: Grand Fireball" Itachi called before exhaling a fireball of gigantic proportions which burned through the trees separating him and his target, in the distance Itachi saw the explosion but didn't drop his guard.

"Gomu Gomu no: Jet Pistol!"

Narrowly dodging thanks to his Sharingan managing to track the figure darting around the clearing Itachi took the time to appreciate how much Luffy's Second Gear had improved but he still wasn't using all his potential.

Dodging a few more blows, Itachi countered by imbuing his forearms with Armament Haki and waited for Luffy to over extend a punch which he punished by pulling him in and chopping him on either side of his throat effectively cutting off his airways. With Luffy temporarily disorientated Itachi drove a Haki imbued knee into his gut which curled the young captain up, to finish up the combo Itachi rolled over Luffy's back and once his feet touched the ground he grabbed him by the scruff of the collar and threw him into a tree which snapped at the force of the impact.

Itachi not waiting for Luffy to get his bearings or recover began rolling through a string of hand seals. "Water Style: Water Bullet" Itachi called as he spat a medium sized ball of water at Luffy prompting the rubber man to dart to the side. Luffy landed and rolled until he was a decent distance from Itachi, Luffy was catching his breath and trying to come up with a plan.