The aftermath of Gray's humiliation still hung in the air as the guild slowly cleaned up the battlefield. Lucy Heartfilia sat at the bar, hands cupped around a fresh drink Mira had given her to "steady the soul."
Because honestly… she needed it.
Kai—Kairo Sunveil—was leaning against a pillar nearby, idly flicking a coin between his fingers while the guild tried not to look at him too hard. It wasn't fear. More like that instinctive respect one gives a casually sleeping tiger.
Lucy watched him from the corner of her eye. She hadn't spoken to him properly yet.
He seemed relaxed, almost lazy. But beneath that slouching posture was coiled strength—movements so quiet and light that he almost faded into the surroundings when he didn't want attention.
Also, he'd stolen Gray's underwear mid-sentence.
Lucy swallowed.
*I should introduce myself… maybe.*
Before she could gather the courage, Kai's golden eyes shifted toward her.
She froze.
Then his head tilted slightly, as if he were studying her. Or scanning. Or calculating.
He pushed off the pillar and walked over.
Lucy felt her heartbeat accelerate.
*Okay, okay — stay calm. He's just another wizard. Just another guildmate. Just—*
"Hey," Kai said lazily, stopping a foot from her, hands in pockets. "You're the new one."
Lucy straightened. "Ah — yes! I'm Lucy Heartfilia. It's nice to meet you!"
Kai blinked once.
Then his eyes drifted down to her belt.
Specifically, to the set of Celestial Spirit keys hanging there.
Lucy instinctively stepped back. "Uh—?"
Kai hummed in interest. "Those are… interesting."
Mira immediately shouted from behind the bar, voice sharp with warning:
"Kai! Don't you even *think* about touching Lucy's—"
Kai was already gone.
Not a blur. Not a flash.
Just gone.
Lucy looked down and gasped.
Her keys were missing.
The guild erupted.
"DON'T LET HIM TOUCH THEM!!"
"HE'LL TAKE THEM APART!!"
"KAI, COME BACK WITH THOSE!!"
Kai appeared standing on top of a table, Lucy's keyring dangling from one finger. He twirled it like a toy, examining each key with a fascination that bordered on obsessive.
"These are… old craftsmanship," he muttered. "Rough, under-optimized. Gold ones are decent though. The silver ones could definitely be improved…"
Lucy panicked. "G-Give them back!! Please!!"
He didn't seem to hear her. Instead, he reached into his pouch with his other hand and pulled out—
—something.
Wires? Metal scraps? A crystal? Did he carry an entire workshop in that tiny pouch?
He pressed the junk to her keys and Lucy felt her knees go weak.
"Oh no oh no oh no—!!"
Cana shouted: "LUCY RUN! THAT'S HIS *TINKER* LOOK!"
Levy screamed: "THE LAST TIME HE USED THAT FACE HE MADE A BOMB !"
Kai turned slightly, eyes focused, pupils dilated with excitement.
"Perfection requires trials," he murmured.
Lucy nearly cried. "T-TRIALS?! ON MY KEYS?!"
She lunged toward him, but Kai moved like smoke — that shadow monk fluidity that made him almost intangible. One moment on a table, next moment behind Lucy, tinkering away.
"No, no, stay still," Kai said absently. "You're shaking them. I might fuse something wrong."
"THAT MAKES IT WORSE!!" Lucy wailed before continuing." Please don't break them kai those are my friends it's the only thing I have of my mom".
Her voice cracked. Actual tears welled in her eyes.
Kai paused.
His hands stilled. He blinked once, then finally looked at her face.
Her trembling lip. Her wide eyes. And the genuine, terrified worry.
His expression softened.
Slowly — deliberately — he stopped whatever he was about to do. His posture relaxed fully. The scraps and crystals vanished back into his pouch.
He gently placed the keys back into her hands.
"Here."
Lucy clutched them to her chest, gasping in relief.
Kai shrugged. "Didn't touch anything. Just looked."
"Y-You scared me…" Lucy whispered, wiping her eyes with her sleeve.
Kai gave a lopsided smile, just a hint of guilt buried under playful bravado.
"Sorry. Sometimes I forget people don't like their belongings exploding."
"That's not an apology!!" Lucy shouted, tears still streaming.
The guild roared with laughter.
Before Lucy could scold him further, however—
**The front doors slammed open.**
Loke ran inside scared shouting."everyone erza is back."
A wave of presence rolled through the hall — powerful, commanding, unmistakable. Natsu and gray quickly sat down all the fighting stopped.
Lucy turned and saw the red—the armor—the glare.
**Erza Scarlet had returned.**
She strode inside, dragging a giant monster horn behind her like it weighed nothing. Conversations died. People froze. Natsu tried to hide behind Happy. Gray scrambled for his clothes.
Erza scanned the room broken tables and spilled drinks."I was gone for a while and i already received so many complaints about our guild destruction of property, beating the client, stealing the liquor the list goes on ."
Her eyes looked over everyone."Elfman sit down in one place, macao and wakaba stop drinking and take a job, loke stop harassing girls and natsu, gray where are you."
"Here". Two sets of voice appeares and much to lucy shock natsu and gray were sitting together hand on each others shoulder.
Erza nodded." Good I see you have stopped childish fights."
Then finally her eyes locked on Kai.
"Kai."
"Red."
Erza's brow twitched. "Don't call me that."
Kai shrugged. "You don't like 'Red'? It suits you. Fiery. Aggressive. Easy to spot in the dark."
Erza's glare sharpened. "If you call me that again, I will tear your shadow apart thread by thread."
Kai stretched, yawning. "Can we do this later? I already used my delayed magic today."
"You will answer me now," Erza countered, stepping forward. "I heard you destroyed half the hall before noon."
"Not half," Kai corrected casually. "Maybe a third ,half of it was done by gray because he froze the floor and natsu because he was breathing fire."
The two mentioned boys stood up. Gray shouts"You stole my underwear you freak."
Natsu also growls." And you shoved his dirty unwashed underwear in my mouth."
Gray hearing natsu call his underwear unwashed slams his head against natsu." What that hell you say flame brain I wash my underwear everyday."
Natsu growls back ." Oh yeah then why does it smell like rotten eggs maybe you should wash yourself more then ice stripper."
But their argument was cut short when erza shouts."Enough i heard what I needed to, kai are you going to fix everything you destroyed or not ."
Kai just continues playing with his gadgets ignoring her as he waves her off." Yeah I will do it later i have already used my delay magic for today I already told you."
"Then do it with your hands now" Erza repeated." or else we can do it the old fashioned way "as she grabs her sword.
Kai sighed dramatically.
Then a lazy grin formed.
"Fine. But hand to hand. No magical weapons. No fancy armor tricks." His eyes gleamed teasingly. "Unless you need them I won't mind ?"
Erza stiffened.
The guild collectively winced.
Bait set.
Hook prepared.
And Erza bit hard.
"You arrogant—! Your think I can't " She requipped instantly, appearing in her standard Heart Kreuz armor as she lunged at him with her blade.
Kai's grin sharpened.
The fight began.
**The Red Knight vs The Shadow Monk**
Erza swung hard, but Kai threw something from his pouch before the blade could reach him — two tiny pellets, barely the size of marbles.
"What—?".Erza growls jumping back.
They burst.
One exploded in a flash of blinding white light.
The second detonated in a shock of vibrations that rattled Erza's armor like a struck gong.
The air trembled.
Erza's stance broke.
Her vision blurred.
"W-What—? My balance—!!"
"Improvised gadgetry," Kai explained, already in front of her. "I call them Disruption Pellets."
Erza's teeth clenched as she tried to swing her sword through the haze, relying on instinct.
But Kai slipped inside her guard with effortless fluidity.
Her blade descended—
—and his left hand caught her sword swinging hand's wrist mid-swing.
She pivoted and swung with her off-hand.
His right hand snatched that wrist too.
In a single, seamless motion, he stepped behind her leg and swept her off balance.
Erza gasped as she toppled backward.
But she didn't hit the ground.
Kai's grip held her upright, wrists pinned safely but firmly and her back resting on his leg.
Their faces were inches apart.
The guild watched in stunned silence.
Mira clasped her hands together and squealed, "So romantic!"
Kai barked a laugh."don't make this wierd white".
Erza's face turned crimson."get off you asshole".she didn't waste a second her leg shot upward like a cannon hitting kai in he chest.
Kai flew backward, arms flailing—
—but instead of hitting the ground, he twisted midair, his body floating as if it was a weightless as he smirks wiping the dust off his chest." Feather fall for the win."
He landed as softly as falling paper.
The guild cheered.
Erza stood, regaining balance—
—and realized her right boot was missing.
Kai twirled it on his finger.
"You fight better barefoot," he observed.
Erza's aura spiked with murder.
Lucy whispered to Mira, "Who is that woman?!"
Mira smiled calmly. "That's Erza. One of our S-Class mages. Strongest female wizard here she uses requip magic alongside her different sets of armours that enchance her abilities."
Lucy felt her jaw drop. "She's S-Class?! Then Kai is he also an S cl—"
"Oh, Kai isn't S-Class. He is same as natsu and gray he uses tinkering magic which allows him to engineer and make gadgets using various stuff using his magic he can make many different things he is one of last few of tinker mages left so you might have not heard of it, it is also why he was so intrested in your keys."
Lucy blinked. "He's… not a s class and neither a fighter but a engineering type?"
"Nope he is trained is monk and assassin arts although he was kicked out of both after he broke a lot of rules and destroyed many places during his testing or pranks. So Master Makarov refuses to rank him."
"W-Why?! He's insane!"
Mira sighed. "He is kai."
Lucy had no idea what that meant.
"Enough games," Erza growled, summoning a ring of swords around herself. "I'll end this. Requip Heaven's wheel "
She rushed forward, steel orbiting her like a lethal storm.
Kai stepped calmly, almost rhythmically, as his arm wrappings shimmered — and unraveled as he mutters."Shadow Style: Wrappings of the Serpent"
They whipped outward like dark, flexible serpents.
The swords clashed against the wrappings.
Metal cut nothing.
Erza not the one to be disappointed dodges through the wrappings tangling them with her swords and reaches kai and swings at him but kai raises his hand the wrappings tighten around his foreams as he blocks her cuts .
Erza's eyes widened. "I can't slice through—?!"
"Shadow Monk wrappings," Kai explained, weaving between her blades. "As flexible as cloth, strong as enchanted chain mail."
Before erza could think something kai pulled something from his pouch he starts to mash them together as sparks explode from his hands as she froze jumping back but it was too late." Tinkering arts : Improvised gadgetory spring coil binds." As he throws a bunch of small pellets towards her. Erza grabs her sword throws them cutting through each of the Pellets before they reach her but as she about to cut another pellet she felt her instincts go off and sliced behind her where kai had appearsd from shadow as he blocks her strike with his forearms wrappings impressed." Your sensed my shadow step good job red."
Erza didn't waste time on talks rushing at him and swung her sword from the left horizontally, Kai dropped back supporting himself with right hand on the floor as her sword passes where he was and the very next second his left leg shot at erss face with a kick which she blocked with her forearm although it pushed her back she didn't waste a second rushing at kai before he could get on his feet, kai realising this didn't bother getting up and went for a sweep kick at erza who jumped over it and smashed her leg down at where he was but kai still down kicked back as well both their drop kicks hitting each other and kai used the force to roll back but as he sat erza was already there and kicked him straight he managed to block it with crossing his arms over hai chest yet the force still launched him through a bunch of tables
But while Erza was busy getting her breath after finally managing to hit kai, she didn't notice several wrappings slithering behind her.
Wrapping her legs.She realises tried to cut them but more kept wrapping her legs again then her arms.
Binding without pain — but cutting off movement.
"Tch—!" Erza strained, trying to break free.
Kai appeared before her in a blink slightly bruises here and there and his bangs falling messily as he moved.
His hand chopped down on her right bicep.
Her arm went limp.
Before she could recover, he grabbed her left arm with and delivers a chop strike at her left bicep.
—and followed by striking her temple with a right elbow.
Her vision blurred.
Then his foot rose from below.
**CRACK**
A clean upward kick to her chin launched her skyward.
The guild gasped as Erza spun in the air.
Kai shadow-stepped above her, flipping gracefully. His leg extended, descending—
**ECHO STRIKE — AXE KICK**
It landed square into her stomach with a hollow thud followed by another strike out of nowhere due to the echo strike enhanced by the prayer beads that sparked unpredictable magic—this time lightning.
Erza's body spasmed from the numbing jolt as she shot downward.
She crashed through a table, rattling the floor.
As dust settled in the arena everyone looked nervous calling for erza worried.
But Erza was already pushing herself up, shaking the numbness out of her limbs.
Kai descended lightly, landing beside her—
Holding her sword in his hand.
"Hmm hey red," he mused. "How much would this sell for as scrap metal?"
Every vein on Erza's forehead bulged at once.
"KAAAAAAAAAIIIIII—!!"
She charged, swinging the swordless fist she still had control over. Kai didn't move until she was inches away.
Then her fist reached his face but erza fist passed right through his face as she realised "Shadow image" but she was not given the time to ponder it as she saw kai appear right beside her.
His knee shot into her stomach.
The breath left her.
Then his foot swept behind her again, pivoting smoothly.
He leaned close, whispering in her ear—
"Gear up, Red this if for the kick you gave me when I was down."
She froze realising what he meant and then his boot connected squarely with her backside.
**BOOM**
Erza flew forward like a crimson missile, tumbling through multiple tables.
Lucy screamed. Natsu choked . Gray winced out of sympathy. Cana roared with approval at winning her bet. Mira sighed into her towel.
Dust settled.
Erza laid there face first in a new armour as she stood up slowly.
Barefoot. Hair wild. Armour dented at her butt—matching Kai's boot shape.
She had managed to requip mid-blow, saving herself from worse.
But her expression…
Lucy gulped.
"That… is the face of a woman trying not to commit murder," Mira whispered.
Kai put his hands in his pockets.
"Good match."
Erza pointed at him with trembling fury.
"Kai… you… are… insufferable."
Kai smiled lazily. "Thank you."
"That wasn't a compliment!"
"You sounded impressed," Kai said, stretching his neck.
"I WAS NOT—!!"
"Could've fooled me."
Erza looked one breath away from exploding.
Then she sighed aggressively, brushing dust off her armor.
"I'm going to shower before I deal with you properly."
Kai yawned. "Sure. We can fight again later."
Erza froze.
"…I hate how accurately you use that phrase 'later' ."
Kai winked.
Erza marched upstairs, radiating an aura of barely-contained rage and reluctant respect.
**Aftermath**
Lucy sat down hard, keys clutched to her chest.
"Kai is insane," she whispered.
Mira giggled. "You get used to him."
Lucy stared at the destroyed tables. The scattered swords. Remembering Erza's dented armor. Kai humming as he tinkered with a pellet like nothing happened.
"No," Lucy said, shaking her head. "No one gets used to that."
Mira smiled warmly.
"We all did."