Scarecrow: Defender, Impostor...Littlest Brother

Yo! I'm Hatake Kakashi.

Some gore is described, there will be a small warning beforehand. Also, 2100+ words! HAVE FUN!

Kakashi had left Dawn Island with Ace three years ago, when he was twelve. He didn't stay long though, opting to leave the freckled teen once he deemed him safe, with a good crew and a powerful Devil Fruit. He stayed a few months after that for good measure—or, according to Ace, because he wanted to finish a full year to appease his slight OCD. Excuse him, Kakashi did not have any OCD. He left his eldest brother with few parting words on the eve of his birthday.

("Flame teleportation." The smaller said with a smirk before vanishing off the deck and was across the waters to the island they'd just left behind, leaving an ecstatic Ace to develop a full D-shaped grin. Oh, all the pranks—)

(But that is for another time.)

The second year was spent wandering around the first half of the Grand Line and stumbling across a very interesting group. Kakashi decided to stay. Of course, he'd left one time to visit Luffy for a while on his birthday and to check up on the straw-hatted boy before returning, quickly climbing up the ranks in the third year before Luffy set off. The rubber teen should be on his way right now. How convenient was it that Mr. Zero had sent him back to the beginning to take care of business?

("Can I oversee the mission with the Five Pair?" He asked the Den-Den Mushi.)

("...Mr. Six, you have been ordered to stay as backup in—" the mature voice of Ms. All Sunday began to explain, but Kakashi had already hung up.)

When he'd finally arrived at Whiskey Peak, he'd pegged his targets with a simple location tag that basically left an imprint of his chakra on the person for a few days. Seeing as no one (so far) has the ability to use, maintain, or detect chakra in this world, it was fine if he left tiny temporary imprints here and there.

("...How did you know it was me?" Kakashi asked the chakra-less old man warily. He'd asked Garp the same question, but the Vice Admiral only laughed and never answered the question.")

("You're too young to learn Haki, boy." The old man, Neguri, had said, ruffling Kakashi's hair. Kakashi had ducked away, brows furrowed.)

("What if I need to protect my brothers from it?")

("That's likely where you'll learn it.")

(Kakashi looked at his smaller hands, frustrated. "Haki...")

(It's been years since then and Kakashi still doesn't know-)

He left the town undetected within the same ten minutes he'd arrived, greeting the whale before settling in the shade of the lighthouse. Laboon was up and awake again. Hopefully he won't scare his brother's crew too much.

—-meanwhile, at the top-—

"Nani the hell is that?!"

"Cool! It's huge!"

"It's a mountain?!"

"A wall!"

"Against what?"

"Newcomers, maybe?"

"Who would pay to build that?!"

"Not Nami."

"Damn straight!"

*whale noise*

"A whale??"

"That's a whale?!"

"How can that possibly be a—it is!"

"The boat won't turn!!"

"Luffy! Do sOMETHING—!"