So this was some random thought I had the other day and I decided to write it up before I forgot about it – this is the Tamers as the Warriors! I really don't know where this thought came from but it sounded cool – it's not gonna be exactly the same as Frontier but this will have the same basic plotline and a few situations will be the same but overall it will just be a sort of crossover-AU. Enjoy.

This is weird. A whole train station under another train station!? Why did that voice bring a bunch of kids here?

These were the thoughts of a young boy standing in an elevator staring out at the many children and trains gathered in the hidden station. He had light skin, light brown hair and light red eyes. He wore a blue hooded shirt over a white t-shirt, with long grey shorts, yellow wristbands on his hands, and green converse sneakers. He also had yellow goggles over his forehead. His name was Takato Matsuki.

He hesitantly stepped out of the elevator and onto the platform – guess I have to catch one of the trains – looking around at the multicoloured vehicles, he decided upon a maroon coloured one and headed towards it.

Whatever possessed him to follow the orders of a voice on his phone, he didn't know what it was – his gut maybe? – was probably the same thing that was forcing him to run for the now departing train and was more than likely the reason he took the huge risk of jumping over the railing and onto the back of the vehicle. He watched as the rest of the trains left, leaving only a few children in the station waving some people off but having the sanity to not go where their phones told them.

As Takato got his balance, he exhaled a sigh of relief and jumped slightly when he made eye contact with a young boy on a black train next to his. The kid was no older than four and he just stared right back at Takato before a tunnel blocked their views of each other.

Takato hummed in curiosity and opened the door to enter the actual train carriage. The first one he entered was empty and absolutely silent; he could hear a few muffled sounds coming from the one in front of him though and opened the door to see four people doing multiple different things – none of them sparing him a glance as he awkwardly entered.

There was a girl about his age sat by one of the windows on his left. She had pale skin, brown eyes and shoulder-length brown hair which was worn in a ponytail on her left side and a green hairclip. She wore a yellow shirt under a green dress, yellow socks, and white and cerulean sneakers. She also had a yellow dog sock puppet with a red mouth, pink ears, black nose, and dark brown eyes on one of her hands.

Across from the girl was a boy that looked a little under a year older than him. He had light olive skin and dark blue eyes as well as spiked up brown hair. He wore a purple, short-sleeved, button-up shirt, brown trousers and black shoes with yellow stripes on the side.

At the opposite side of the carriage was another boy with tanned skin, short blue hair and grey eyes. He wore a sleeveless orange vest with a zipper over a black t-shirt, brown pants, black socks, grey and yellow shoes with white soles, and white wristbands. He was pacing back and forth biting the top of his thumb.

Finally, there was a young girl who looked about five; she had lightly tanned skin, brown eyes, and shoulder-length brown hair, which she wore in pigtails with red hair ties. She wore a pink shirt with long sleeves under a wine-coloured dress and pink sneakers with white soles. She was curled up in a ball on one of the seats silently crying.

"Um... Hi..?"

The four in the carriage finally stopped and turned to look at him. He froze for a moment as all eyes focused on him.

"Who are you?" The older girl asked, standing from her seat.

"Uh, my name's Takato."

"Nice to meet you" the girl responded with a small smile, "I'm Jeri."

"Are you guys here 'cause of the voice?" Takato questioned, holding up his phone.

"Yeah" the boy at the back answered, "you haven't by chance seen a little girl, have you? About her age" he pointed towards the sniffling girl next to him, "or a boy a bit younger?"

Takato shook his head with an apologetic look before snapping his fingers, "I did see a boy – he was on a different train though"

The boy groaned loudly, dropping his head into his hands.

"You okay there, bud?" the older boy asked, "I'm Ryo... by the way."

"The name's Henry. This is Ai – I was babysitting her and her brother along with my sister when we got the message. Those two ran off the minute we got down here and the two of us were pushed onto this train – if Mako's on another train, I can only hope Suzie's with him."

"I'm sure they're okay," Jeri said reassuringly, "maybe they ended up with some people our age, I mean; look at our match-up."

"I hope you're right" Ai sniffed, hugging Henry's leg tightly.

Takato looked around the train car once again and did find the whole group rather interesting, it slightly made him wonder if his two classmate-best friends were on one of the many trains, they may have even been with the two missing children for all he knew, though that would have been a weird stroke of luck or a crazy coincidence. From the corner of his eye, he saw Henry pick Ai up and rest her on his hip, the brunette could only wonder how he was feeling; losing his sister and another kid he was probably close to must've hurt and made him feel pretty guilty.

The train jolted, breaking him from his thoughts as the lights flickered and dimmed, the vehicle throwing all its passengers within the carriage back towards the door Takato had come in from initially; he squeezed his eyes shut as his back hit the cold metal of the carriage wall, but opened them just as a strange figure ghosted over him for a moment. His head snapped over to look at the others beside him, his eyes growing to saucers as bodies flashed over theirs too; a multitude of gasps echoed through the carriage as lights appeared in front of each of them, hand-sized devices falling into their laps as the train settled down and the space filling back up.

Takato looked at the gizmo resting on his legs; it was slightly rounded but still quite angular and was mainly a silver colour, the top half had a small screen inside a deep green hexagon with pronounced corners. The bottom half had a deep green grip, there were two white buttons beside it above one small green one and another white button sat on the side of it.

Looking at the others, he found that theirs were all the same as his but had varying colours: Henry's was mainly black with dark grey decorating all of the pieces that were green on Takato's, Ryo's was blue and yellow, Jeri's was pink and purple, and Ai's was light green and light blue. Slowly, the five of them stood, staring at the devices in their hands once more before looking up and at each other.

Henry was the first to speak; shoving his gadget in his pocket with his phone and shifting Ai in his arms as she put her own away, "what have we gotten ourselves into?"

"I hope nothing too bad..." Jeri whispered, loudly enough for the others to hear as she hid her device away and her puppet's face scrunched together as her hands tightened in worry.

Ryo let out a quiet noise of wonder as he stared out of one of the carriage window, the others turned to stare at him, slowly making their ways over to similarly stare out in awe as white, marshmallow-y blobs flew through the sky outside, mixing with the clouds and reflecting the sun.

"Woah... they look like ghosts," Takato murmured, leaning against the back of the seat to get a proper look at the creatures.

From their views through the windows, the children could catch a glimpse of the big station and the fiery metal city that the train was approaching. With cheeks pressed to the glass, the five of them watched the new area grow closer and closer until the train stopped at the station and they warily made their way to one of the doors. The steel entrances opened with mechanical hisses, a large gust of wind dumping the children from their waiting point and onto the hard station floor with cries of alarm, surrounding them was a group of round grey creatures with large ears and narrow red eyes.

"Welcome to the Digital World kids," the train piped up.

Ai, let out a scream, curling into Henry as he and the others turned to stare wide-eyed at the train.

"D-Did that just talk?" Jeri squeaked, pulling her puppet closer to her face as if to hug it.

"Hey! I'm not a that, I'm a Trailmon. I'm as alive as you pipsqueaks, though I am more handsome than you lot," the creature sounded offended, enough so to insult them all, "Anywho, you're in the heart of a Digimon Village so make the most of it; there ain't a lot of 'em left anymore."

"What the heck is a Digimon?" Ryo questioned, being to first to stand from the heap on the floor.

Before he could get an answer, Ai started sobbing. Henry stood, letting her curl up in his arms as he rubbed her back to try and calm her down, he looked at the others apologetically, not that any of them ridiculed him or Ai.

"Is she okay?" Takato asked quietly, standing as well, the girl's sobs dying to little sniffs as she exhausted herself, Henry moving his hand from her back to her hair.

"For the most part," He responded just as quietly, "she didn't really wanna come here in the first place, but with Mako and Suzie running off we had to."

"Sorry you're stuck, kids, I gotta go. If you wanna go home you'll have to find a Spirit with those D-Tectors or something!" The Trailmon said, backing out of the station and disappearing back down the track.

"Well he was informative," Ryo huffed slightly, folding his arms over his chest and looking at his four companions, "wonder what a Spirit is."

Jeri was the last to get to her feet, brushing herself off with her puppet-less hand, "he gave us some information about where we are... and I guess a Spirit is our only way home, and we need these D-Tectors to get them," she said, holding up her device for a moment before putting it away again.

"Guess we're alone now," Takato hummed, rubbing his wrists and looking around. Those grey creatures (of which he assumed were what Trailmon called Digimon) had disappeared and all he could see was the expanse of the metallic village they were apparently at the heart of.

"What do we do then?" Henry asked, Ai finally calming down properly and just staying curled against him.

Apparently, this Digital World didn't want them to get answers at that moment, because just as Takato was about to suggest something, a blast of green fire came in their direction, forcing the five of them to separate onto the tracks. Out from the light came two Digimon, screaming at each other frantically as they ran from whatever was chasing them. They looked near identical aside from their colour schemes, they both looked like big bunnies: one was cream with one spike coming out of its head and green markings with (strangely enough) a brown leather backpack on its back, the other was brown with pink markings and three spikes coming from its head, both had large ears that would drag on the floor if they weren't running. With everyone spread out along the station track, Takato was the one the two collided with, the three of them falling in a large heap with the boy yelping in surprise.

"Hey look, a human!" The cream one gaped, pressing its nose to Takato's and staring in interest.

"You think everything's a human," the brown one retorted, his voice far cuter than Takato expected it to be.

"I-I'm a human! C-Could you get off, please?" The boy stuttered, lifting his torso up by his elbows as the two Digimon clambered off him with small apologies.

Takato looked to his left to try and see the others, but all he saw was more streaks of lime flame. The pair of Digimon that had run into him hid behind his legs when he stood, a large shadow appearing in the flames and coming towards them.

"What is that?" He gulped, staring at the large dog that slinked from the shadow and flames.

"That's Ceberumon," the brown rabbit said, tugging on Takato's shorts, "that's why we need your help – we aren't strong enough to defeat him ourselves."

"Where is the ancient Spirit?" Ceberumon growled, "I can sense its presence all over this town. I must destroy it!"

"Uh... no way, it's mine!" Takato shouted, feigning confidence as the cowering Digimon laughed nervously.

"Then you will be destroyed with it! Emerald Blaze!"

The inferno shot at the trio, Takato holding back a scream as he bolted out of the way, running onto the floating, thin tracks with the rabbit Digimon on his head and the reptile following with claws digging into the boy's shirt. Granted, it wasn't one of Takato's greatest ideas, he didn't really have anywhere to go now, and if he fell he'd probably die and if he didn't, be hurt like hell. Ceberumon appeared at the edge of the station, staring at him and the other Digimon like prey (which, let's be honest they were by this point), he watched as Ceberumon breathed out fire onto the tracks, breathing in some sort of code that made the entire section disappear.

"Takato!" Jeri yelled in panic, seeing him slip down the tracks and land on the stone ground below it.

The boy groaned, lifting himself onto one elbow to rub his head and stomach. From next to him, his D-Tector beeped and pointed towards a large pillar of silver light, within the pillar a small statue appeared.

"What is that?" He asked quietly.

"The Spirit," the bunny with the backpack breathed, staring in awe, "The Spirit of Steel."

"Well, that was easy... I suppose. How do I get it? What do I do with it when I get it?"

Ceberumon appeared behind them, chuckling darkly, "no need to worry about that, for it will soon be destroyed!" He leapt over the trio, Takato panicking and just grabbing the Digimon's tail as they disappeared into the pillar of light.

Takato opened his eyes, not even realising he'd closed them. His head shot around frantically, finding Ceberumon standing in front of the Spirit with a sinister smirk, he was about to yell out in protest but something incredibly strange happened: something slashed at the Digimon, cutting into him like a knife against butter, causing him to scream in pain and leap out of the pillar.

Takato stared wide-eyed for a second before turning to look at the statue, something clicked inside him and he called out to it, holding his hand out and feeling the familiar weight of his D-Tector slip into his grip. Pointing it forward, a beam of light shot out and centred on the idol, absorbing it into his device and awakening an unfamiliar power.

"Execute! Spirit Evolution!"

A cocoon made from streams of data surrounded him, a transformation, unlike any other taking place. Takato felt a power surge through his whole being, he grew taller and his limbs and clothes changed. When the cocoon cracked open, a completely new thing stood there: He was far taller than he was previously but still quite slim, the majority of his body covered in glittering steel armour, like that of a medieval knight. His hands were covered by emerald and ruby gloves, his feet shielded in similarly coloured boots, over his chest was a green poncho covered in red triangles and while most of his head was covered in steel, his glowing rose eyes could be seen through a grated cover. On his back, was a large, circular shield made majorly from a mirror, and on his left hip was a long katana, protected by a forest green sheath.

"Kinzokumon!"

Everyone in the surrounding area stared at him in awe and disbelief at this tall Digimon standing in place of the nervous boy from before, he looked rather impressive.

"What's this!?" Ceberumon questioned incredulously, "a human turned into a Digimon!"

"You go Takato!" Ryo cheered from above, Henry and Jeri smiling as well with Ai watching in wonder.

"What'd he turn into?" The little girl asked, twisting in Henry's arms to get a better look.

With those big ears of theirs, the two Digimon that fell with Takato looked at each other before the brown one opened up the backpack the white one had and pulled out a large book. Opening it up, the two flicked through a couple of pages before the white one read a few things.

"Slim and kinda green... big fan of swords... Kinzokumon!" He purposefully spoke louder for the sake of the four watching from above.

Ceberumon sneered at the Digimon, eyes narrowed and fangs flashing against the sun, "it doesn't matter who you are, you'll lose!" He barked, lunging forward with another cry of, "Emerald Blaze!"

Kinzokumon easily moved out of the way, leaping over his opponent and lifting the two bunny-like Digimon up into his arms, moving them to where the others were and allowing them to cling to Henry and Ai before leaping back down to face Ceberumon.

"Portals of Darkness!" The beast snarled, holes appearing all around the pair.

Kinzokumon did his best to jump away from the portals, but his luck soon ran out and fell into one, disappearing from sight. Within the dark realm, Kinzokumon looked around frantically, crying out in pain when several slashes to his chest alerted him of Ceberumon's presence.

"You're in my realm, child."

"I will beat you," Kinzokumon retorted, determination clear in his shining eyes and silky voice. He took a moment to breathe, grunting at another slash before he pulled his shield from his back and caught his opponent's claws within the mirror; he lifted the shield over his head slowly, pulling the weight of Ceberumon with it before the mirror glowed a brilliant silver, "Echo Shot!" More of Ceberumon's leg was absorbed into the shield before being thrown out with a loud metallic screech, being thrown from his realm and into the air of their previous one. Kinzokumon followed, jumping into the air next to him and pulling his katana out in one swift motion, "Iron Slice!" It was like the blade moved at the speed of light, being returned to his sheath almost immediately with a ring of code surrounding Ceberumon as the pair slowly lowered to the ground.

"A human child defeated me!? No!" Ceberumon cried out with his last moments.

Kinzokumon pulled out his D-Tector, pressing down on the button on the side of the device and sucking in the data with a huff of happiness. Landing back on the ground in front of the others, he dropped to his knees and changed back into Takato who was panting heavily whilst the others gleefully cheered for his success.