The guild hall was still buzzing from the absolute chaos of Kai and Erza's earlier duel when Erza Scarlet returned. With her hair still damp from a fresh shower and wearing a brand-new suit of armor, she marched through the doors like a scarlet storm. She moved with an intense, burning purpose that made even the rowdiest members instinctively straighten up. You could practically feel the atmospheric pressure in the room drop.
Lucy blinked, feeling the sudden, heavy seriousness settle over the room. So this is Erza when she's not fighting Kai…
Erza didn't even glance at the broken tables and splintered wood still scattered across the floor from her fight with the spatial mage. That alone spoke volumes about how focused she was.
"Everyone," Erza announced sharply, her voice cutting through the remaining chatter. "A Dark Guild is currently on the move toward Oshibana Train Station. Their exact target is unknown, but we cannot afford to be lenient. There is no telling what they are planning—especially since, from what I have gathered, they have a cursed artifact in their possession. I cannot disclose every detail here, but this is a matter of utmost gravity. With Master away at the conference, we must handle this ourselves."
The room tensed instantly. Even Mirajane paused mid-cleaning, her bright smile fading. Natsu and Gray wore grim expressions, though a spark of competitive excitement flickered in their eyes.
But one person reacted instantly.
Kai, who had been lazily leaning backward on his chair—precariously balancing on only two legs—suddenly let the chair slam forward onto all fours as he stood up straight.
"An artifact? Cursed?" His golden eyes sharpened, the lazy demeanor vanishing in a heartbeat. "As in, one of the cursed artificial demon crafts of Zeref?" A wide, feral grin crept across his face. "Now that… is interesting."
Lucy blinked, looking between him and Erza. "You actually know what that is?"
Kai shrugged nonchalantly. "Cursed constructs. Living souls embedded into metal. Ancient, forbidden enchantments. One-of-a-kind magical engineering." His tone dropped into a low, thrilled hum of pure excitement. "Of course I know it."
Of course he does, Lucy thought, a sweatdrop forming on her brow. She was quickly starting to realize that Kai always seemed to know things he technically had no business knowing. The manic, brilliant glow on his face right now was the exact same look he had when he successfully swiped her Celestial Spirit gates keys.
Erza's left eye twitched the absolute second she registered the look of mad-scientist glee on his face.
"Kai," she warned, her voice dropping into a low, commanding register. "You are not coming."
Kai blinked, pointing a finger at his own chest with an expression of mocked innocence. Who, me?
"Yes," Erza snapped, crossing her arms. "You."
"Too bad," Kai said, already taking a casual step forward. "I'm coming."
"No, you are not."
"Yes, I am."
"No, you're—"
"Yes."
"I said NO!"
"Yes, Red." He reached out, casually tapping her armored shoulder as he passed. "Don't stress your pretty head. We'll discuss your delusional thoughts regarding my absence later."
Erza sucked in a sharp breath, looking like she was actively preparing to blast Kai straight through the guild's back wall.
"You are forbidden," she said, enunciating every single syllable with terrifying clarity, "from touching, dismantling, analyzing, fiddling with, poking, prodding, unscrewing, un-enchanting, breathing near, or even thinking about whatever that artifact is."
Kai just nodded absently. "Did you say something, Red? No? Great. See you tomorrow."
He walked straight past her, completely unfazed. It was as if she hadn't spoken a single word.
Erza twitched violently, her gauntlets clenching into fists. "I WAS NOT DONE TALKING!"
Kai kept walking, waving a dismissive hand over his shoulder.
Lucy whispered in absolute awe, "H-He just walked away from Erza… and he's still alive…"
Gray shook his head, looking almost sympathetic. "Idiot's got a death wish. One of these days, she's actually going to bury him."
Natsu just shrugged, resting his hands behind his head. "Nah, this is pretty normal for them."
"BOO!"
Suddenly, a horrific, demonic-looking mask slid directly into Mirajane's peripheral vision.
Mira shrieked so loudly the glass windows rattled in their frames. Reaping upward in pure reflex, her heel caught the edge of a table leg behind her, sending her off-balance.
Kai moved in a brilliant blur.
In one smooth, impossibly fluid motion, he caught her securely around the waist—albeit dropping his hand a little lower than strictly necessary—while simultaneously catching three toppling beer jugs with his free hand.
"Whoa there, White. Careful now."
Mira blinked away a few startled tears, clutching her chest. "K-Kai!! Don't scare me like that!"
Kai smirked, setting the jugs safely back on the bar. "Where's the fun in that? besides, it was just a joke."
Mira let out a heavy sigh, looking at him and thinking, He really is just like always. However, her relief quickly evaporated when she realized exactly where his hand was firmly resting.
"Kai… That is not my waist," Mira said, a sweet but terrifyingly strained smile gracing her lips through clenched teeth.
Kai hummed thoughtfully. "Huh. It isn't?" He looked down, squeezed slightly, and then burst into loud laughter. "Oh man! And here I was thinking you'd put on a bit of weight—good to know it's just your as—"
"STOP TALKING!" Mira shouted, blushing furiously.
She swung a swift punch at him, but he simply vanished from thin air. Mira stumbled forward slightly, completely flustered, as he reappeared a few feet away, strolling toward the tables while casually whistling.
"I hate you, Kai!" she cried out after him.
"Love you too, White!" he called back cheerfully. As he bypassed Erza, he added with a grin, "Red, learn something from White—wait, actually, don't. Diversity is charming. It'd be boring if I couldn't rile you up this way."
Erza sputtered, her face flushing red for an entirely different reason.
Elfman hurried over to help his sister, caught in a classic dilemma between his manly duty to protect her and the fact that Kai was his friend. Besides, Mira actually seemed more lively and energetic when Kai was messing with her, even if she was currently embarrassed.
"You okay, sis?" Elfman asked, scratching his head.
Mira nodded, her usual gentle smile returning. "It's nothing, Elf. You know how Kai is."
From across the room, Cana's voice chimed in. "We all do. He's an absolute asshole." She smirked, taking a swig from her mug. "But a lovable one."
"Good save, my friend. I was just about to bite you," a voice whispered right in her ear.
Cana, completely lost in her drink and not realizing where the voice was coming from, just hummed absentmindedly. "Honestly? I might have liked that."
But her smirk completely vanished when her brain caught up to her ears. She froze, turning around to find Kai suddenly sitting right behind her. She panicked, choking violently on her alcohol as Kai laughed warmly, patting her back to help her clear her lungs.
"Oh, take it slow, my semi-nude alcoholic," Kai teased. "It would be shameful if our drinking queen died from choking on her own liquor."
Cana, her face bright red from coughing, glared at him with watery eyes. "What the hell was that, you idiot?! Can't you speak up before you sit behind someone?!"
Kai stared at her, looking thoroughly amused. "That is exactly what I did, fart-for-brains. Actually, I—"
Suddenly, Kai stopped talking entirely. He went dead silent, his golden eyes locking onto Cana's face.
Cana looked at him, completely confused by the abrupt shift. "You what? Hey, you still in there? Why are you staring at my face like that?"
Kai leaned forward, his expression deadpan but intense as he raised a hand toward her face, muttering softly, "Nothing… I was just staring at the most beautiful person in this world."
Cana's entire face flushed an intense crimson. She stuttered, "Eh-h? What? I—"
Embarrassed, she quickly tried to turn her head away, but Kai gently caught her chin with his fingers, turning her face back toward him.
"Don't turn away, Cana," Kai murmured softly. "How else am I supposed to look at my reflection if you close your eyes?"
As the cheesy punchline finally settled in, Cana froze.
The entire guild hall erupted. Kai laughed loudly, slamming his hand on the desk, while Macao, Wakaba, Laki, Max, and the other members howled with laughter.
"You fell for the same old trick again, Cana!" Macao mocked, wiping a tear from his eye.
Mira and Erza just sighed in unison, while Lucy watched the display, a mix of amusement and sheer bewilderment on her face.
Cana's face burned with pure anger. "You damn jerk—!"
But before she could even swing her fist, Kai had already vanished, reappearing behind her and throwing his arms playfully around her neck. He laughed as she tried to elbow him, easily dodging her half-hearted blows.
"Sorry, little one," he chuckled, leaning his chin on her shoulder. "I just thought you'd be offended if I didn't greet you properly, seeing as I already said hello to Salamander, the Stripper, Red, and White."
Cana finally calmed down, letting out a defeated sigh and stopping her attempts to hit him. "I would have heavily preferred it if you just ignored me instead of doing… whatever that was."
A second later, Kai vanished from behind her again. Cana sighed, rubbing her temples, but as she looked down, her eyes landed on two pristine bottles placed neatly on her table. They were centuries-old, rare preserves that only high-status nobles could afford for high-end galas. She suddenly remembered offhandedly telling Kai to keep an eye out for them during his last solo mission.
I hadn't thought he would actually take that seriously, she thought. A soft, genuine laugh escaped her lips. What was I thinking? It's him. Of course he'd act like a dramatic idiot just so he doesn't have to look mellow while giving me a gift.
Over at the bar, Lucy whispered to Mira, "Is… is this always normal?"
Mira wiped a stray tear of laughter from her eye. "He actually used to be much worse."
Lucy looked horrified. "Worse?!"
Mira added softly, her expression turning warm, "But he's not actually mean. Just… I guess you could call him 'Kai-ish'. And speaking of Kai, Lucy, why don't you join them on this mission? It will be a wonderful experience for you to learn from our strongest."
Looking back at the chaotic spatial mage, Lucy somehow understood exactly what 'Kai-ish' meant.
The Train Station Incident
The next morning, when the group gathered at the train station, Lucy nearly tripped over her own feet.
First, it was because Natsu and Gray were already screaming and clashing first thing in the morning while Happy watched them with a sigh. Second, it was because of Erza.
Erza stood on the platform looking like a literal, one-woman moving company. The bags and luggage were stacked so high they soared past her head. There were swords strapped across multiple trunks, shields, armor chests, mysterious crates…
"Exactly how long is this mission supposed to last…?" Lucy muttered, sweating bullets.
Erza turned around, offering a bright, disciplined smile. "We must always be prepared for any eventuality! Although, I believe we have never properly introduced ourselves. You are our newest member, correct?"
Lucy nodded, her posture going stiff. "Yeah! I'm Lucy. Mira told me it would be a good experience to learn the ropes by going on a mission with you guys."
Erza patted her shoulder with enough force to make Lucy's knees buckle. "It is an honor to meet you, Lucy! Ah, I remember you now. You are the remarkable rookie who defeated a monstrous gorilla with a single finger!"
Lucy stood completely dumbfounded, staring at Erza. "I… I did?"
Behind them, Kai strolled over leisurely, hands tucked into his pockets, carrying absolutely nothing but his tiny, enchanted leather pouch.
"Hey," Kai called out lazily. "My favorite walking junkyard has finally arrived."
Erza's eyebrow twitched violently. "Call me that again, Kai, and I will requip into an armor that you will thoroughly regret."
Kai leaned in close, a smirk playing on his lips. "Red, everything you requip into is something I regret."
Lucy immediately slapped both hands over her mouth to muffle a massive burst of laughter. Natsu, Gray, and Happy weren't so quick to hide it; they ended up laughing out loud, which promptly earned all three of them a swift, synchronized punch to the head from Erza.
As they were finally preparing to board the train, Natsu suddenly turned to Erza, a challenging, competitive smirk plastered across his face.
"Oi, Erza! I'm only coming along on one condition!" Natsu yelled, pointing a fiery finger at her and Kai. "You and Kai have to fight me after we get back! I'm gonna defeat you, and then I'm taking revenge on Kai for throwing Gray's underwear into my mouth!"
Erza actually smiled back, a spark of warrior pride in her eyes. "I admire your confidence, Natsu. Very well. Once we return safely from this mission, I will gladly grant you a proper spar."
Kai just shrugged, walking right past them toward the train carriage. "Sure, why not? But if you lose, you have to put that exact same pair of underwear in your own mouth willingly. If you agree, I'm in. Or, you know, you can just back out now if you're scared."
Natsu hesitated for a fraction of a second at the disgusting condition, but the moment Kai suggested he was scared, fire erupted in the Dragon Slayer's eyes. "YOU'RE ON, YOU FREAK!"
Happy just let out a heavy sigh. "Aye… he fell for the bait instantly."
Gray, meanwhile, was growling in the background. "Why the hell are you guys putting my clothes into your stupid bets?!"
Inside the train compartment, Erza began unloading half of her armory onto the surrounding seats. Kai sat cross-legged right beside her, leaning his head back against the window as if gravity didn't apply to him.
Lucy glanced at Natsu, whose face was already turning a sickening shade of green before the train had even fully left the station. She turned to Gray on her other side and whispered quietly, "Hey, if Erza hates him so much, why is she sitting right next to him?"
Gray hummed quietly, keeping his eyes on the window. "Probably so she can hit him faster the exact moment he does something to annoy her."
As Erza began laying out the details of the Dark Guild, Natsu slumped further into his seat, looking progressively closer to death.
Lucy leaned forward, genuinely worried. "Natsu… are you going to be okay?"
He let out a pathetic groan, sliding down until his head hit the seat. "I am dying… save me…"
Erza sighed heavily. "As usual… I suppose I'll just have to knock him unconscious to ease his suffering—"
"Hold on," Kai said, raising a hand to interrupt her. "No violence just yet. Let me test something out. This is a perfect opportunity."
Kai reached into his tiny hip pouch.
…and he kept reaching.
…and reaching.
…and reaching.
Lucy's eyes went wide as saucers as his arm went entirely up to the shoulder inside the tiny bag. "How big is that thing?!"
Kai didn't even look up, his face deadpan. "Ask me that in the bedroom, blondie."
Lucy choked on her own saliva, her face exploding in a bright red blush. "I DIDN'T MEAN—THAT'S NOT—!"
Erza let out a long, weary sigh, her own face dusting with red. "Ignore him, Lucy. He says incredibly stupid things when he doesn't want to explain his magic."
Lucy stopped, surprised. "Really?"
Kai still didn't look up, rummaging deeper into the pocket dimension. Metal clinks echoed from the bag. Glass vials rattled. Springs boinged. Gears turned. A random duck squeaker sounded, followed by something that hissed angrily, and a device that inexplicably mooed.
"W-What is he even doing…?" Lucy whispered, thoroughly terrified.
Gray just sighed, leaning his head back. "Improvised gadget time. Just look away, Lucy."
Natsu, pale and trembling, shook his head weakly. "No… no way… I don't want… anything he built in ten seconds… I refuse—!"
Suddenly, Kai mashed a glowing magic crystal, two loose screws, a copper wire, and a piece of metal that looked suspiciously like a children's toy into his palm. He squeezed, and his hand erupted in brilliant flashes of blue spatial light as the materials forcefully fused together.
"Kai…" Lucy whispered, both horrified and utterly amazed by the blatant disregard for natural alchemy. "That shouldn't even be physically possible."
Kai hummed softly. "Lots of things shouldn't be possible, blondie. I do them anyway."
He held up a strange, glowing, metallic sphere over Natsu.
"No," Natsu whimpered, trying to crawl backward up the seat. "NO! GET IT AWAY FROM ME! I'M FINE, I'M CURED—!"
Erza simply reached out, grabbed Natsu's jaw with an iron grip, pried his mouth wide open, and said, "Hold still, Natsu."
"Wai—mmph!! Erza donn do thiis—!"
With a practiced flick of his wrist, Kai dropped the makeshift gadget straight into Natsu's mouth.
The device pulsed with a faint light. Natsu spasmed violently for a fraction of a second—
ZAP!
Then, a look of profound, eerie peace washed over his face.
"Oh," Erza blinked, releasing his jaw. "It actually worked."
Natsu sat perfectly still, his eyes blank and completely relaxed, as tiny wisps of steam lightly drifted from his ears.
Kai nodded, satisfied, as he dusted off his hands. "It does have a minor side effect: an occasional, paralyzing electric shock every few seconds to reset his inner ear equilibrium. You can spit it out if you prefer the motion sickness, lizard boy."
ZAP!
Natsu twitched like a ragdoll, but a shaky, triumphant smirk stretched across his face. "Hell… hell no! This is way… ZAP… better than the sickness!"
Kai shrugged. "Yeah, you get a few jolts now and then, but hey—no motion sickness."
Lucy stared at Kai as if he were some kind of unexplainable supernatural phenomenon. "It… it actually worked? You're a genius!"
Kai looked over at her, raising an eyebrow. "What were you expecting? I made it. Though, fair warning, it does have a slight chance to explode and permanently paralyze his jaw. But the odds are low."
Lucy's jaw dropped, horror replacing her awe. "It can explode inside his mouth?!"
"Probably," Kai admitted easily, leaning back against the window.
Another loud ZAP shot through Natsu, who stiffened up like a board before slumping over.
Erza sighed, clapping her hands together to regain control of the car. "Let us stop discussing the structural safety of Kai's inventions. We have far bigger problems to deal with than Natsu's motion sickness."
Finally, the atmosphere turned serious. Gray, Natsu, and Lucy leaned in closer as the train sped along the tracks.
"Alright, Erza," Gray said, his face hardening. "What is it? You said you would tell us the details once we were underway."
Kai also nodded, rubbing his hands together in pure, unadulterated excitement. "Yeah, for a change, I actually agree with the idiots. Do tell, Red. What is the name of this lovely little artifact?"
They all sighed, clearly seeing that Kai was infinitely more interested in tearing the ancient artifact apart than actually stopping the Dark Guild from using it.
Erza took a deep, steadying breath, her expression darkening as she spoke the forbidden name.
"It is the demonic mass-murder flute… Lullaby."