Brave Little Soldier Boy, Come Marching Home
Not my usual stuff but a friend (Abyssboo) and I had a brainworm so like...
Flins-is-a-Shroud au oneshot, Genshin Impact x TWST crossover
No trigger warnings needed
2,752 words
Crossposted on ao3 here
Spencer is the only OC in the fic and my Yuusona
Have fun :)
Kyryll Shroud AU masterpost HERE
~~~~~(Fic Start)~~~~~
“For the last 10%, do whatever it takes, just bring the moon down.”
“At this point,” Dottore drawls, expression blank, “what can you hope to do about it?”
A new voice suddenly interrupts from behind. “Not as much as I can, I’d assume.”
“Flins!” Aether cries, relief palpable as minor tension drains from his shoulders.
“Well that's interesting. Just how did you escape?” Both Flins and Aether ignore the pointed question, the fae leaning in partially to conceal his words from The Doctor, and partially to keep himself from falling. His clothes notably more tattered, and a long gash stretching down his previously unmarred cheek.
“If this plan of mine works out the way I hope it does,” Flins smiles, though it comes off as more of a grimace. Aether reaches up to help brace Flins as the taller leans heavily on his shoulder. “Then you should aim for anything that looks like a bottle. That is my best chance of survival.”
“Flins, what-” They’re interrupted by a slow clap from above. Dottore’s face impassive as he stares the pair down.
“An intriguing notion. Now, prove your hypothesis.”
The fae turns to face the Traveler, giving him a final regretful bow, before limping back into the empty arena with squared shoulders and a chin held high. “My final gamble. I am, as they say, going all in, and shall place my bets on you. Let me reveal my final card.” Flins’ lantern flickers into view in his hand as his eyes begin to glow, black liquid beginning to swirl around his feet and drip down his face. The gem embedded in the handle, typically glowing with an eerie purple light, now seems to suck the color from its surroundings. “Come, fear not that which goes bump in the night, for I shall be thy Guiding Light.”
All sound is sucked from the area as the liquid explodes and swallows Flins, swirling rapidly before sloughing off, leaving the fae to consolidate its mass behind him. The formal uniform of a Ratniki replaced by a battered cuirass of unfamiliar yet ancient origin. Dented and damaged greaves sit snugly over worn sandals, tattered half cape swaying in an invisible breeze. His wrists, now bound in heavy manacles, drag large chains connecting him to this new monster. The being itself is a terrifying form, an impression of three hooded figures floating behind Flins, each with a rounded, pale head that gleamed like moons.
The transformation ends as abruptly as it began, and Flins launches himself at The Heretic with a feral roar, forcing him onto the back foot as the two begin to trade blows with renewed fervor. “THIS EXPERIMENT ENDS HERE!”
With Dottore now suitably distracted by a feral Flins and whatever that monster is, Aether dives for the formula, grabbing it off the ground and immediately sidestepping out of the way of one of Dottore’s beams to cradle it to his chest, quickly assessing for damage. Finding none, he lets out a breath of relief. “Thank goodness.” Warily, Aether picks his way across the arena, staying low while making his way over to Pulonia’s collapsed form. He slides up to the mech in a crouch, gently placing the formula next to it’s head.
Aether watches warily from his new viewpoint as laser and lightning strikes fill the arena, the fighters getting faster, seemingly disappearing in a flurry of blows and rattling of chains. A glance at the sky reveals the formula now in motion, though still incomplete. The moon, bathed in an unearthly pale yellow glow, falling rapidly towards the false sky.
“NO!” Dottore roars, stretching a finger to begin re-sealing the sky, only to be immediately interrupted by a chain lashing excruciatingly tight around his wrist.
Flins’ face is twisted into a snarl, ink flowing freely down his cheeks as his eyes swirl with flame. “Your fight is with ME.” The rampaging fae plants and spins on his heel, drawing the chain closer and swinging, an attempt to throw Dottore over his shoulder. Countering, the false god digs his heels in, severing the chain with a blade to gain distance again. Flins continues to chase him down, a twisted game of cat and mouse zig-zagging across the platform.
Despite the length of the fight growing longer, the opposing forces only seem to grow stronger as they go. The resulting shockwaves batter into Aether as he digs his sword into the ground, clinging to Pulonia tightly. The slate in his hand gleams faintly, and after checking it one last time, a cheeky grin grows on his face.
“Dottore!” Aether pushes himself to full height once more, Luonnotar appearing in a flash behind him as the fighters pause and turn to stare. “The moon will never be yours.” At this, the moon has smashed into the edges of the false sky, sending shards of red raining down. Pulonia’s visor glows a blinding teal, the equation finally complete. Columbina Hyposelina appears in a whirl of kuuvahki feathers, soaring down from the sky to settle lightly next to him.
“I’m back.” Columbina smiles, Aether goes to return it, only to freeze when a growl of pain thunders across the stage. The pair turns, faces melting into horror, relief immediately replaced with fear.
With the Doctor frustrated over Columbina’s return it should’ve been the best chance for Flins to get a good hit on him, only— Flins was, ah, wrong. The moment the moon had shattered the sky, it seemed as if he had frozen in place. Not only that, but his limbs were turning red and jagged, flickering just like the edges of the false sky.
And then, with a victorious snarl and a snap of Dottore’s fingers— he, and the swirling abyssal monster, were gone with an abruptly cut scream. “Well, that certainly levels the playing field, hm?” The heretic remarks with equal parts amusement and annoyance.
“What did you do to him?!”
“I merely sent him back where he belonged.”
Idia sighs, absentmindedly dropping materials into his cauldron. “Why did I leave my room today? There’s a new limited gear I was gonna grind for! This throws off my schedule completely!”
His desk partner snorts, stirring with one hand and scrolling on his phone with the other. “Cause it’s a test day?” Cater drawls, “And a little robo-birdie told me you totes can’t afford another failed assessment.”
“Ortho’s a fuckin snitch who shouldn’t be trusted.” Idia grumbles, sending Cater into a fit of muffled laughter and earning a warning glare from Professor Crewel.
A large explosion suddenly shakes the building, and almost sends the pair tumbling to the ground. “I didn’t mess up our potion that badly, did I??”
“No, it came from outside!” At this, the majority of the class stands, crowding the windows in an attempt to catch a glimpse.
Crewel’s hand slams into his desk, making the room jump. “SIT!” His glare intensifies, scowling. “Stay here until the Headmage sends the all clear. Anyone who doesn’t will be tending the greenhouse till they graduate.” Cold grey scans the room, landing on the pair in the corner. “Shroud, Diamond. Come with me.” With that, he whirls from the room, coat whipping behind him in his haste.
Cater and Idia glance at each other, sharing confused looks, before scrambling to follow Crewel out. “I mean, I understand bringing Idia cuz he’s a housewarden,” Cater huffs, him and Idia almost jogging to keep up with Crewel’s brisk pace. “But why me?”
“Don’t assume me ignorant, boy.” the professor snaps, “use that Unique Magic of yours to alert the faculty and other housewardens. Shroud, we’re off to assess the situation.”
A muttered “I am him, and he is another. Split Card!” later and multiple Caters peel off, racing down the corridors. Once the group reaches the doors, Crewel slams them open, revealing the cause of the commotion. Idia whimpers, staying firmly behind the teacher as they stare out into the courtyard.
“What the fuck.” A rampaging man, heavy in the throes of overblot and roaring in pain and anger. The blot phantom looming tall, a dark and imposing trio of figures draped in cloaks and gleaming chains. “Not good!”
“Stay back.” Crewel orders, readying his magestone and positioning himself in the doorway.. “We engage once the Headmage arrives.”
“IL DOTTORE!”
“Who the fuck is Dottore?”
“WHERE IS DOTTORE?”
Idia yelps as he tumbles forward, clutching the tablet to his chest as he narrowly avoids another arc of electricity. “This is absolutely NOT normal! Where the hell did he get all these speed buffs and shock boosts?!”
“Just stay back with me! The sooner we ID this dude, the better!” Another crash of lightning separates the group again as the blot-stricken man roars, leaving Idia with Spencer, crouched behind a now-crumbling statue in a desperate attempt for cover.
Crewel’s voice carries strangely over the field, barely audible among the continuous strikes of lightning and clanging of chains. “Cater and Azul! Force him towards the stadium! Leona, Riddle! Keep him off balance! Floyd stop going for the man’s head! Bad pup!”
Spencer’s eyes narrow, flickering back and forth as they watch the rampaging man tear through Cater’s clones like putty. “Crowley you have to stay back too! I’m pretty sure he thinks you’re this Dottore guy!”
“I shall be fine!” Crowley declares, streaking forward flanked by Azul and one of the Caters, cloak flapping wildly and hat lost to the winds. “I’m more worried for the rest of the students if we cannot contain him!” A small whimper is lost to the storm. “And the property damageeee.”
“Suck it up!” Trein barks from across the green, holding strong to a shield spell as electricity rains from all angles. “First we must figure out the who and how! Does anyone recognize him?”
Cater yelps, summoning another clone as one is poofed by the blotter while shoving Azul out of attack range. “It’s a no from me, chief!”
“There’s an easier solution.” Leona grunts, straining under the weight of a chain as his magic races to dissolve it. “Just get the Radish Sprout to run a face scan! Someone get him a picture!”
The battle devolves from there, frantic attempts at corralling the unknown man turn into a mass of Cater clones with multiple borrowed phones attempting to get a clear image of his face. In return the man roars in frustration, chains and electricity arcing wildly. “WHERE IS THE DOCTOR HIDING?”
“Say cheese!”
“Not quite.”
“Mind staying still?”
“Smile for the camera!”
Holy shit holy shit holy shit, Idia wheezes, clutching the screen like a lifeline, staring frozen at the influx of images from Cater as the last color drains from his face. “KYRYLL?!”
Spencer freezes, lowering their makeshift slingshot to grab Idia’s shoulders and shake. “You know this guy?”
Idia opens his mouth to respond but gets cut off with a yelp as Spencer suddenly drops flat, dragging him down with her. The whiff of wind is audible overhead as the blot chains whip past, slamming into and ripping a nearby lamppost out of the ground. “Go, go, go!” He hisses, yanking the Prefect back to her feet and shoving her in the direction of a ruined cluster of benches farther from the fight.
Once safely under cover, Idia finally has the chance to answer Spencer. “I thought he—” he gestures at the edge of their cover, towards the chaos. “—was dead!”
“Oh, shit.”
Idia slowly turns his head to meet their eyes. “Spencer-shi, you don’t understand.” Hands trembling with adrenaline, Idia zooms in on the face, image sharpening onto a familiar feral grin as he does. “That’s my older brother.”
“Fuck.”
The fight tears on around the pair as they sit in a moment of silence, breathing heavily. Spencer is the first to break it, slipping a surprisingly unbroken phone from their pocket and beginning to text frantically.
“I really hope Cater’s phone has survived so far because I still don’t have everyone’s numbers.” She pauses, reading something, before cursing and peeking out from the makeshift cover. “Aw shit, I think he finally grabbed someone- IS THAT CROWLEY?”
“Wait WHAT?” Shock overriding the fear of being hit, Idia joins Spencer, watching the scene in muted horror.
Chains tighten around the Headmage as his shield shatters, dragging Crowley sharply towards the man, dangling him in front of the being at eye level. The blotter’s face twists, squinting as he pulls the hanging Crowley closer with a clawed hand. Frustration is evident when he cannot find what he was seemingly looking for. “You….are not Il Dottore. Where is he?”
“I’ll do you one better!” Spencer calls from her perch, ignoring Idia’s frantic attempts to drag her back down. “Who is Dottore?”
“Spencer-shi please, the reference isn’t worth it!”
Crowley is flung to the ground none too gently as the man slowly turns, scanning the ruined grounds around him before turning his gaze to the sky and freezing. “This is not Nod Krai.” He continues his slow turn, eyes narrowing further as he seems to finally take in the uniforms of the students. “You are not Fatui.”
“The fuck is a nod krai? Or a ‘tui-whatsit? C’mon Mr. Knifefish! It was just getting fun!”
“Floyd?”
“Wassup Sea Lion?”
“Shut the hell up.”
“Where did he-” The baffled man’s train of thought is abruptly interrupted by shattering glass, a shining arrow piercing the phantom and shattering the trio of bottles in a sudden cacophony. Immediately, the blot begins dissipating, sending the man crashing to the ground, unconscious.
Spencer waves at the forest line, cupping their mouth to project her voice to the figure perched there. “A shot of true beauty, darlin’!”
Deep breath in. Exhale. The tension bleeds out of Idia’s shoulders as he slowly loosens his death grip on the tablet and slumps to the ground. “I’m so not built for this final boss bs dude.”
“Tough shit,” The Prefect snarks, already stretching down to drag him to his feet. “If you want a chance to confirm your theory, ya need to do it now. ‘Else Crowley’ll probly do sumthin stupid.”
Groaning, Idia accepts the hand and stands to approach the downed man slowly, taking in the strangely foreign uniform and wicked looking polearm. “And that didn’t kill him, right?”
“Nah,” Spencer draws, sidling up much faster than Idia did before crouching next to the man’s face, seemingly studying it closely. “He’s just out cold. Happened to the rest of em’ too. Hey, I think I can see the family resemblance.” Her finger traces the shape of his eye and jaw, before motioning at the wild mass of purple hair splayed around the man’s head.
“And we’re absolutely sure this isn’t a mass hallucination caused by the first years in Alchemy this morning?” A hand flies up to smack the back of his head. “Ow! Spencer-shi that hurt!”
The Prefect snickers to herself, standing and patting the debris off their clothes. “Least you know it’s real now.” They pat Idia's shoulder, wandering over to the curious stragglers regrouping now that the danger has seemingly passed. “I can buy you maybe ten minutes, bucko. Pony up and get your shit together.”
Idia blinks slowly as they leave, taking a deep, shuddering breath to steel himself before facing the man again. Slowly reaching out, he gently pokes a cheek. And again. And again. “U good? Spencer-shi said you’d be ok but not how fast you’d respawn.” As he reaches out again, his finger is suddenly grasped by the gloved hand that had been on the ground just a moment before. A strangled yelp escapes before Idia can stop it, his instinctive jerking back halted by the strength of the grip.
The raspy voice that speaks is achingly familiar. “This had better not be another one of your mental games, Il Dottore.”
“Ew.” Idia’s nose scrunches as he not-so-subtly attempts to remove his finger from the man’s death grip. “Ngl that guy sounds sus af. Can you sit up or did Rook’s KO crit?”
“So it wasn’t a blot-driven hallucination.” Sharp teeth are revealed as his mouth widens into a fanged grin. Hooded eyes blink open as a piercing yellow gaze locks onto Idia. Lean but strong arms trap him and he melts into the all-encompassing hug. “How many years has it been? It’s so good to see you again, little brother.”
“Kyryll!”
“Did that dude just call Idia ‘little brother’?”
“Shut the fuck up and don’t ruin their reunion.”
“Yes ma’am.”