Disclaimer: I don't own Kingdom Hearts or Fairy Tail.

Summary: Lucy receives a set of thirteen platinum keys. Figure the rest out for yourself.

Update Schedule: Sporadic and at my own convenience. In other words, slow. Also, I'm making this up as I go along. So yeah.

Author's Note: I had a dream. This is the result. Must stop eating ice cream before bed. Also got inspiration from Opening Dangerous Gates (Bleach x Fairy Tail crossover) by LadyD0544. I recommend it if you are familiar with both fandoms. If only Fairy Tail, well, I still recommend it - the Shinigami have... interesting personalities.

This is after the Grand Magic Games, but before whatever is happening right now. I kind of forgot everything that happened after that.

I also put "Humor" in the genre section... But I'm not really sure if this counts as humour. It's lighthearted, I can tell you that... But I'll try to make it funny!

Thirteen Keys

Number XIII - Roxas

[ The Key of Destiny ]

Lucy jumped into the fountain screaming, avoiding a set of very large claws from the oddly cute shadow demon that was her job to kill.

They - Natsu, Grey, Erza, Happy, and Lucy - had taken an S-Class job to hunt down unknown shadow demons that had been terrorizing the town of Jackalore for months. The reward was ten million Jewels and a set of never-before-seen platinum Celestial Spirit keys.

Of course Lucy just had to get those keys.

In fact, the dangers of the job didn't fully register until they encountered three of the demons in the middle of the town square in broad daylight. The townspeople had frozen and then ran into the nearest buildings like they had done it a thousand times before. (In all likelihood, they probably had.)

The rest of the team didn't even bat an eye when dozens of other yellow-eyed demons stepped out of the shadows.

"What is this!" Lucy wailed. "They don't even leave bodies!"

"It seems the townspeople were correct," Erza remarked thoughtfully, wearing her Heaven's Wheel armour and casually slicing a demon in half. It dissolved into particles of darkness. "I myself have never seen these kinds of demons before. They are probably an undiscovered species. Fascinating."

"Heh, they're not so tough," Gray grunted. "Ice Make: Lance!" An ice lance slammed into a shadow demon creeping up Lucy.

"I have three!" Natsu yelled in glee, punching another demon with a flame-covered fist. Happy cheered for him from above.

Lucy coughed out a thanks, smoothed out her skirt, and stood. She steeled her nerves and picked out a Gold Key from her collection. "Open, Gate of the Golden Bull - Taurus!"

Taurus appeared beside her in all his massive muscular glory. Without prompting, he charged at... Lucy's breasts. "Ahhh so perfect!"

"Get in there and kill those demons!" Lucy yelled. She lunged to the side, barely avoiding another set of claws.

"Noo! How dare you hit Lucy's perfect body!" Taurus roared and beheaded the shadow demon. He then proceeded to swing his axe everywhere, hitting all incoming shadows and accumulating collateral damage.

"Well... At least he's fighting," Lucy muttered.

Soon, all the were defeated. None of them even had a scratch. Except for Lucy, who skinned her knee when she jumped into the fountain, but that didn't count.

Natsu scoffed and proclaimed, "That was easy!"

Erza nodded. She Requipped into her casual Heart Kreuz armour. "Indeed. Come, let's report to the mayor."

Lucy remembered why they chose the job in the first place and cheered.

"That was very impressive," the Mayor of Jackalore praised. The Fairy Tail team were in the Mayor's office, a large room surrounded by books with a humongous mahogany desk in the centre. A floor-to-ceiling window took up the wall behind the desk, letting in natural sunlight and showcasing the now-destroyed town square. The Mayor didn't seem too bothered by the damages.

"It was nothing," Natsu grinned.

"As for your reward..." the Mayor rummaged through his desk and produced a bag containing ten million Jewels and a keyring containing thirteen curious Platinum Keys. He handed them to Erza, who passed the keys to Lucy.

Lucy gawked at the Platinum Keys reverently. They were truly never-before-seen, as no one had ever heard of platinum Celestial Spirit keys. The keys had identical handles forming a vague upside-down heart with a pointed cross on the top. Each of them had Roman numerals from I to XIII engraved in the centre and unique designs on their teeth. They all hummed with a strange power that felt otherworldly to Lucy.

"Thank you so much," she whispered. These keys... Whatever they summoned, they were powerful, she could tell. Possibly even more powerful than her Gold Keys.

"Those look cool," Natsu commented, peering over her shoulder. "Can't wait to fight against them."

"Natsu, you are not going to - "

A scream interrupted Lucy's scolding. Alarmed, the Mayor and the mages scrambled to the window and blinked as hundreds of demons attacked the townspeople. Except the cute ones weren't alone. Accompanying them were various incarnations of shadow demons, all with the same red cross-hearted design somewhere on their bodies. There were the normal cute ones, as well as ones in various colour-coded dresses. There were ones that flew, ones that had antennae that reached the floor, and ones that were as big as houses. Shadow demons that wielded weapons and musical instruments alike crawled from the darkness. Large, fat ones covered in armour easily deflected projectiles from those who tried to fight them.

Overall, it was a very scary sight.

Lucy was well aware of her hanging jaw.

"Oh my," the Mayor said faintly.

"Che, we'll take care of them," Natsu said cockily.

Gray nodded while Erza just hummed in agreement.

"E - Eh?" Lucy managed. "All... Of them...?"

"And don't worry about the payment," Erza added. "Our job is to eradicate these shadow demons, after all, and it seems we missed a few."

"A few..." Lucy wondered what Erza's definition of "many" was.

"Let's go!"

And that was how Lucy found herself cowering behind a barrel, separated from her team, nursing a sprained ankle, and her normal set of keys stolen by one of the floating demons. She didn't even have her whip - it slipped from her hand while she fought a floating green shadow demon.

A fat armored one stomped past.

"Ooh, I am so dead," she mumbled. She patted her pockets once again for something useful... And heard the familiar sound of clinking metal. Puzzled, she pulled out a key ring... And her recently-acquired Platinum Keys.

She stared at it stupidly for a moment, wondering how they got there. A crash from behind her barrel jolted her out of it.

But she didn't know how to use these keys. Didn't know the names of the spirits, or their titles...

She froze as the fat armoured demon lifted her barrel with ease. "Oh..." she said nervously to the demon. It stared at the mage with curious yellow eyes. "So, um, I really don't taste very good... Can you... Go pick someone else to eat...?"

The demon lifted the barrel.

Lucy screamed and dived away. "Waaaaaaahhh!" Instinctively, she picked out a Platinum Key, pointed it at the demon, and yelled, " Open, Gate of the Key of Destiny - Number XIII: Roxas!"

A burst of light - blinding white light - and the summoned spirit appeared.

Lucy blinked, clearing her sight, and gaped. "Whaa... How...?"

The spirit - how the heck did I do that? - was a confused blond-haired, blue-eyed boy in a black leather hooded coat. "Huh?" The boy caught sight of the demon and summoned two strange weapons that vaguely resembled giant ornate keys. He swung the black one at the demon's head and it burst into black smoke. Lucy continued to gape when a heart emerged from the smoke, floating into the air a short distance before disappearing. That definitely didn't happen when they killed them.

"... Wha - O - Okay." Lucy stood up and faced the spirit. She could feel the draw in her magic. She was still wondering how she knew the name of the spirit - Roxas - but that wasn't important right now. This was also not the time to be forming contracts so... "Okay, Roxas, there are a bunch of shadow demons attacking the town square. You need to kill them," the Celestial Spirit Mage ordered.

The short spirit - whoa, those eyes are blue - stared at her, puzzled. "Do I know you?"

"Yeah - Well, no, but I summoned you. We can talk about this later - Look out!" Lucy dived away again, but Roxas just stabbed the attacking demon and it disappeared. Lucy looked around a saw, horrified, that seemingly all the demons in town were now heading straight towards them.

"Heartless," Roxas murmured, settling into a fighting stance. He held up his black and white keys. "Get behind me."

Lucy did so without question. As much as she'd like to fight with him, she didn't have a weapon, and her sprained ankle meant she couldn't even do a simple Lucy-kick. All she could do was give him as much of her magic as possible to keep him summoned.

The demons - Heartless, Roxas called them - jumped them. Lucy watched in awe as the blond spirit swung his weapons and took out any and all that attacked. His giant keys whirled around, seemingly acting like a homing beacon to the enemies. Every so often Roxas fired a spell from his keys, mostly of the elemental nature although he occasionally cast a healing spell at himself, but he relied on his weapons most of the time.

Eventually all the demons were defeated. Roxas's keys disappeared in a flash of light and he turned to the Celestial Spirit Mage. "Are you okay?"

"Yeah," she mumbled. All those demons - there must've been hundreds - defeated by one spirit? Daaaamn.

"Lucy!" Said mage saw the rest of her team running towards her. Erza, the one who yelled, reached her first and said, "So this is where you were. We were concerned when we found your keys and whip in the fountain and all the demons stopped fighting us and headed here." She threw said items to Lucy, who thanked her.

"You got all the demons," Natsu complained. "I didn't even get fifty of them."

"Wait," Gray intervened, one eyebrow raised, "Lucy got all the demons? Without her spirits?"

"It seems so," Erza confirmed. "This is where all the demons were."

"Lucy got stroooong!" Happy added.

"Umm, it wasn't me," Lucy mumbled, head bowed. "It was him." She pointed at her spirit. For the first time, her team noticed the black-clad blond standing awkwardly behind Lucy.

"You beat all the demons?" Natsu brightened. "I've never seen you before; are you one of those new spirits Lucy got? Fight me!"

"No you idiot!" Lucy, with a burst of strength coming from her protectiveness over her spirits, punched the Fire Dragon Slayer in the face. Natsu slammed into a wall. "Wow Lucy... You got stroooong." Blood dripped from his nose.

"Sorry about that," Lucy told Roxas. "He's an idiot."

"I... See..." Roxas looked around. "There aren't anymore Heartless, just so you know."

"Then our job is done," said Erza. "I'll tell the Mayor. The rest of you, go wait for the train. We have along ride back to Magnolia Town."

"What can you tell me about these keys?" Lucy asked Crux. Fairy Tail's so-called strongest team were now on the train back to Magnolia Town. It was a long, torturous four-hour ride for Natsu.

Crux, a moustached spirit with a giant metal cross for a head, studied the platinum keys and fell asleep.

"Uggghh," Natsu moaned, his face an interesting shade of green. "I... Hate... Trains... I'm gonna barf on Erza."

The redhead punched him.

"Idiot," Gray snickered.

Happy patted Natsu in the back comfortingly.

Crux suddenly awakened. "Interesting..."

Lucy sat up and all eyes were on the Southern Cross. "What?"

"These are not ordinary keys," said Crux. "Nor do they summon ordinary spirits. In fact, they do not summon spirits at all, but rather, Nobodies."

"Nobodies?" Lucy asked.

"Nobodies are the remains of strong-willed beings who have lost their hearts," Crux explained. "The majority of them take on vaguely humanoid white-and-grey forms, and all bear the Nobody insignia." Crux pointed at the handles of the keys. "The stronger the will, the more humanoid their appearance. These are the lesser Nobodies. And then... There are those who retain their original appearance. They look completely human, and it is this kind of Nobodies that these keys summon. There are only fourteen greater Nobodies in existence, and thirteen of them," Crux nodded at the platinum keys, "can be summoned using those keys."

"Wait," Gray interrupted, "what's up with the missing one?"

Crux hummed. "She... is a special Nobody. You will not be able to summon her."

"How did they lose their hearts in the first place?" Erza asked.

"I am not at liberty to release that information."

Lucy raised a hand. "I summoned one of them today, even though I didn't know his name or title. How?"

"It is instinctive, so worry not about learning their names." He paused. "I am out of time. But take note: you do not need to make a contract with them, you can only summon the Nobodies in order of seniority, from thirteen to one - so the next new key you will use will be Number XII - and they will lose their power once you have summoned Number I."

"What!"

"But you can still summon those you've already summoned."

"Oh... That's... Good...?"

Crux nodded and disappeared in a puff of smoke.

There was no noise in the cabin aside from the train and Natsu's groans. Finally, Lucy picked up the Platinum Keys and said, "So... Nobodies...?"

"Sounds interesting," Gray commented.

"You should ask the one you summoned for the rest of their names," Erza suggested. "Just in case."

"His name's Roxas," Lucy automatically answered. "And yeah, I probably should." She picked out the key with the number XIII on it. She scooted to make room on her side, pointed the key, gathered her magic, and said, "Open, Gate of the Key of Destiny - Number XIII: Roxas."

There was that blinding white light again - everyone shielded their eyes - and the blond Nobody appeared sitting beside Lucy. He blinked and looked at the occupants of the cabin in confusion. "Again...?"

"Hey Roxas." Lucy waved a hand in front of the boy. "I'm Lucy, your Summoner. That's Natsu," she pointed at the sick mage, "that's Gray," she pointed at the half-nude boy, "and that's Erza," she pointed at the redhead.

The blue cat raised a paw. "And I'm Happy."

"Umm, hi." Roxas didn't look too sure about the situation. "Why am I here?"

"What're the names of the others?" Gray asked bluntly.

"Gray!" Lucy chided. She looked at Roxas apologetically. "Sorry. We were wondering about the others of your kind. I mean..." She searched for the right words. "There are thirteen of you, right? I'd just like to know their names and titles and abilities so I can summon the right one if I need to. And your name is only one I know right now, so..."

Roxas thought about it and said slowly, "I don't know if I'm allowed to do that..."

"I'll instinctively know their names when I summon them," Lucy offered. "So I'll know it later anyway. I just thought it'd be nice to know beforehand who I'm calling for."

Roxas was still unconvinced. Out of the blue, he asked, "What's the name of this world?"

"I'll tell you if you tell me their names," Lucy bargained.

He glared.

"Earthland," she said, defeated.

"I'll get back to you later," Roxas promised. Then he disappeared in a swirl of darkness.

"What!" Lucy exclaimed, while the others' eyes were wide. "I didn't do that!"

"Summon him again," Erza ordered.

"Open, Gate of the Key of Destiny - Number XIII: Roxas!" The summoned Nobody appeared again, and this time he did not look happy.

"How did you do that?" Erza demanded.

"None of your business," he retorted, and disappeared in a swirl of darkness once more.

Lucy summoned Roxas again.

Roxas disappeared again.

"This isn't working," Lucy sighed. "I'll just ask Crux later. Maybe he'll know a little something."

Crux did know.

But he couldn't reveal that information either.

"Privacy policies," Crux had said serenely.

Lucy sagged. "So... I'll just have to discover them myself."

"Indeed. Also..." Crux trailed off hesitantly, then continued, "As long as those keys are in this world, Heartless - you called them Shadow Demons - will be drawn to its power." The Celestial Spirit frowned. "Well, not all of their power, per se. They are drawn to Number XIII and his weapon, and he comes with all the other keys..."

"Oh," she muttered, "so I'll be expecting some Heartless attacks soon?"

"Precisely." With that, Crux disappeared.

Lucy sank back to her bed. Her apartment, for once, hadn't been broken in by Natsu. Or Gray. Or Erza. Maybe they were tired.

Lucy snorted. Those monsters were never tired. Luckily, she wasn't a monster (she hoped), so she closed her eyes and quickly fell asleep.

She dreamt of white halls, a room with thirteen thrones, and a familiar blond boy reporting to a silver-haired man with amber eyes. He did not look happy.

Next Chapter - Number XII: Larxene