a very /very/ belated crosspost because i just realised that i forgot to add this chapter here, if anyone's even still following it. whoops? mea culpa.
this instalment brought to you by a prompt by swingingrobin on tumblr: "Aoko and Kaito have a power mock-battle. Aoko allows a lot of her water attacks to 'miss' Kaito but she's actually just getting the ground around him really wet. She then tricks him into accidentally freezing the ground. (water + air = ice ?) And guess who loses all of his grace on ice?"
also, art happened! presumenothingDOTtumblrDOTcom/post/158536329810
Saguru wonders, idly, how much Ekoda High budgets for building maintenance every year.
Well, whatever the number is, he's fairly certain it's at least doubled since they admitted one Kuroba Kaito and Nakamori Aoko to the school. If nothing else, the pair wrought merry hell on the ventilation and drainage systems on a regular basis, between pranks and spars and everything that fell in between.
He shakes his head, feeling vague sympathy for the school management, and refocuses on his notebook. Kuroba had suggested a fire tornado, of all things, and Saguru is still trying to figure out if there's any merit to the idea beyond the magician's usual taste for the dramatic.
(It's just as well Kuroba isn't the pyrokinetic here, Saguru thinks with an involuntary shudder, since he'd probably be the kind to regularly breathe fire instead of air.)
Saguru jots down several ideas for testing, though doing it at school is out of the question - if he can figure out how to make a controllable tornado, though…
A stray arc of water flies towards Saguru as he turns a page of the notebook. It sizzles out in a sudden burst of flame.
(The water, of course. He'd never treat his books like that.)
"Sorry, Hakuba-kun!" Aoko calls out sheepishly.
"It's alright," Saguru answers absently, the dome-shaped shield around him already settling back into a barely visible blue flare.
The training hall is empty save for the three of them, as expected. (Saguru doesn't actually know of anyone else who would willingly stay within radius of Kaito and Aoko's spars, and it's virtually become common practice for everyone else in class 2-B to swap places with him when they're drawing lots for training matches in class.)
Saguru looks up at the sound of Kuroba's voice. "Where are you aiming, Ahoko, I'm over here!"
"Well, it's not Aoko's fault that even water wants to stay away from your face, Bakaito!" Aoko replies as she nimbly dodges another gust of wind – it barely ruffles her uniform, but the water jet ends up splashing harmlessly on the floor to join the shallow pool around Kuroba's feet, already two metres across and steadily growing.
(Having Kuroba remain mostly on the ground is one of the only rules he and Aoko have set for these spars. It's ostensibly to avoid any injuries since they aren't using any practice mats, but Saguru knows Aoko mostly insisted on it because she'd probably end up drenching a fair portion of the ceiling otherwise, which would be unpleasant all around.)
Aoko makes a sound of annoyance, and calls up a disc of water instead, which quickly flattens out into a thin sheet as she directs it forward with a gesture.
Kuroba is already on the move, though, with a distinct whoosh of air being displaced as he sends an opposite wave to meet it, and –
Saguru can see the exact moment when Kuroba realises his error, a second too late to do anything, as the water freezes over into smooth ice.
Kuroba flails about in an uncharacteristic lack of coordination before promptly losing his footing to fall flat onto his back, and Aoko grins in triumph.
(…the expression is disturbingly like Kid's, actually, but he isn't about to tell her that.)
Saguru stands up, pocketing his notebook, and walks briskly over.
The thin film of ice now covering the ground is almost completely even, except for where his own footprints have melted a line of shallow impressions, and the web of fine cracks now spreading out from Kuroba.
(Saguru observes the magician – who appears to be trying all at once to stand up, break the ice with air, and figure out what Aoko had done, with varying degrees of success – and wonders if it'd be evil of him to suggest ice to Nakamori-keibu at the next heist. Anything outdoors would be next to useless, of course, but in a confined area where air currents couldn't be manipulated quite so easily…)
"Very well executed, Aoko-kun," Saguru says as Aoko crosses the hall to join them, hands deftly undoing her hair from the bun she'd tied it into. (Long hair was a pain to deal with when wet, apparently, or so she'd told him.) "I'm impressed, you managed almost twice the original area you were practicing with earlier."
Aoko looks over at him, blushing faintly. "Really?"
"I didn't know you were even capable of being impressed, Hakuba," Kuroba grumbles, before falling back onto the floor with an oof.
Saguru exchanges a grin with Aoko, and they speak almost simultaneously. "Now, be nice, Kaito – " " – after all, you do realise which of us is most capable of melting this ice, right?"
Kuroba groans. "You know what, just forget it and – hey, wait, where are you guys going? Don't just leave me here – "
END
MANDATORY NOTE: this is the last complete part of this verse – the following chapters are eternally-incomplete parts that I've written too much of to abandon entirely.
…so how did Aoko do it?
…good question! bad science ahoy! after ¾ of an engineering degree and a considerable amount of googling, the best handwavey pseudo-explanation I can give you is either (a) temperature might have dropped as air expanded to fill the displaced volume, (b) a sharp jump in pressure from shockwaves caused a rise in freezing point, or my current favourite (c ) the previous answers were complete rubbish, and Hakuba Labs just happened to develop some chemical that can increase the freezing point of water. nothing says Aoko needs to use pure water, after all, ha!
which, as I feel compelled to point out, is also nonsense since impurities always lower freezing points, but hey, 400 IQ amirite ¯\_(ツ)_/¯