So after a long time on a hiatus, I've put up this story. To be honest, I don't know when I'll update this story again after struggling for so long with trying to update my other stories. The Celestial Knight and the Demon Heart are still in the works but it's a very slow progress. This story will be heavily AU as a Fairy Tail/One Piece crossover and might just be a series of oneshots pieced together with not as much Nalu action.

More importantly, I hope in this difficult time with COVID-19 that everyone is staying safe and keeping healthy.

As always, thanks for your support.

Disclaimer: I don't own Fairy Tail or One Piece.

The Strongest Monster

It all started in Hargeon Town, on the night of the Lantern Festival where partygoers wandered the streets, faces covered by masks. A young blonde was backed into the wall of the dark alley, her short legs shaking from the fear and adrenaline of trying to escape from her soon-to-be muggers. However, just as they were about to make contact with her, suddenly they were all on the ground unconscious, and a figure surrounded by smoke stood in front of her.

"…Are you a hero?" The little girl who couldn't be older than ten stuttered out.

"Heroes give away all their meat! Why would I want to be a hero?!" The figure bent down to pick up their straw hat.

"Then who are you mister?" She blinked as the smoke cleared and the person, who she now realised was a teenage boy turned to face her.

He grinned, "I'm the person who's going to become the pirate king, Monkey D. Luffy!"

"…thank you for saving me, Mister Luffy."

"Ehh who are you again?" The straw-hat wearing teenager asked nonchalantly,

Little Lucy gasped before immediately bowing her head a full ninety degrees. "I'm sorry for not introducing myself earlier. My name Is Lucy…Lucy Heartfilia."

Watching his reaction with bated breath, Lucy was surprised to see there was no reaction at all, as if her family name meant nothing to him.

"Why are you bowing?" He cocked his head to the side. "You don't owe me money or meat."

"But you saved me. From those bad people."

"Couldn't you take them out on your own?"

"But I'm so small and…not strong like you Mister Luffy."

His jaw dropped. "But I could take these guys down when I was your age!"

Little Lucy slumped to her knees, burying her face in her arms. "I'm a weak monster."

Luffy dropped down beside her, crossing his legs as he tugged at her blonde locks. "Ooh are you?! I have a lot of monsters in my crew! Say, why don't you join my crew?!"

"…you don't hate monsters?" Little Lucy lifted her head, voice part disbelieving but part hopeful.

"Why would I? I've got a green swordsman who uses three swords, one with his mouth! A yellow chef who can make his feet go on fire! A liar! A thief who likes maps and tangerines! A talking reindeer! A smart person who can make extra body parts! A robot! A walking skeleton! And a fishman!" He counted off with his fingers, face split by a smile Lucy would later call his D grin. "And as for me…"

He stretched his arm, and Lucy watched in amazement as his hand plucked two apples from a stall several metres away. "I'm a rubber man! Shishishishi!"

She gaped at the casual theft and the distinct rubbery sound made as he retrieved his arm. Without a moment of hesitation or fear, Lucy gripped the hand without apples and walked straight to the stall, rambling over her words.

"Hi Mister, I just came to pay for the fruit my friend grabbed. He hasn't been here before, so he doesn't know how stalls work." She quickly took out enough jewels along with a little extra and looked pleadingly at the stall owner. Meeting her saviour's face directly, she tightened her grip and immediately bent down at the waist in apology to the owner. "We're both very sorry mister!"

There was muted silence on either side before she felt Luffy also shift and bow his head. Following that, she heard the owner cough awkwardly before waving them away, warning them not to be so reckless in the future. The pair walked away, heading back into the alley where she released her hand, not facing him.

"Sorry for that, Mister Luffy –"

"Luffy. My friends call me Luffy."

She spun around, tears beading in her eyes, surprised to see a small smile on his face.

"Y-You're not mad?"

"When someone's willing to bow their head to protect someone else, that's not weakness, it's strength."

Luffy's smile only grew bigger and suddenly images flashed through her eyes.

Beautiful blue hair streaming in the sunlit air.

The sky bearing witness to a heartfelt wish to meet again.

The promise of eternal friendship marked by solemn crosses on the endless blue.

Lucy shook her head, only to realise Luffy was waving his hand in front of her face, trying to get her attention.

"Neh…so why are you here alone? Got no brothers?"

"I'm an only child. My father is working…and my mother…she passed away."

He turned solemn and without another word, placed his treasured hat on her head.

"She's in a good place so…don't cry anymore."

The blonde only bent her head, hoping the large hat could cover the tears that lingered. Had lingered on since that rainy day.

"When I thought I had lost my brother, a friend told me to remember what I still had. Even to this day, I'll never forget counting each of my crew, the guys I'd trust to have my back. Who's that for you Lucy?"

She bit her lip, thinking so deeply her eyebrows creased.

"…I don't have anyone like that. Father…he doesn't talk to me much anymore."

She peeked beneath the brim of the hat to see his reaction and saw his eyes were closed; arms crossed. He made a deep noise of contemplation. Lucy bowed her head again, realising it was hopeless. Being alone was just her destiny–

"Join my crew."

As if by some ordained fate, the lanterns from the festival were released by the crowds as he said the words and as she looked up at him, his hand outstretched, Lucy felt like she was looking at the sun.

Turn your face towards the sun

And let the shadows fall behind you

"I'm not a strong monster like your crew. I can't fight off bad guys like you. Why would you want someone like me?!"

"Then become the strongest. The strongest monster!"

She watched him open-mouthed as he bluntly said the words as if it were simple.

"What you don't see in yourself, what you don't think you're capable of, whatever you've never imagined was possible for you, you'll do it all when you're in my crew! That's my promise to you!"

"…"

"…if someone like me really is okay…then I'll be your strongest monster…my promise to you…Captain!" Her last word was firm, not seeing the golden particles floating in the air around them due to the strong light of the lanterns.

"Just call me Luffy. You're officially the youngest of my crew then." He put his hands on his hips, properly inspecting her and retrieving his straw hat as he did so.

"The whole crew isn't here so I guess we'll just do a pinky promise for now", he declared as they twisted their pinkies.

"You're one of mine now, Lucy Heartfilia. Your dreams, your sadness, your happiness, I'll carry them all with you! Shishishi! Welcome to the crew!"

Suddenly, his feet began to break down into golden particles, swirling around his body.

"Luffy?! Luffy…who did you say you were again?"

"Captain of the Straw Hat pirates, Monkey D. Luffy. Oh also…"

And he grinned his famous grin before he vanished, only leaving the smell of the sea breeze and a beautiful key, a blend of gold and blue as if the sun was illuminating the sea.

"The Monkey Spirit of the Celestial Sea."

Turn your face towards the sun

And let the shadows fall behind you