Ahem. Do not own KHR. That and this part is already in 'Pieces', specifically chapter nine. I'll give you more soon.
Unicorns are long-known mythological creatures, found in everything from northern European to Indus Valley legends. The descriptions vary, but the most commonly accepted one from Greek and Roman mythos is that of a horse with a single horn, usually depicted as white in art. The most common beliefs held today (aside from it being a mythological magical equine that doesn't exist) is that it is a single-horned magical horse attracted to virgins and capable of healing. These basic beliefs are mentioned in Roman art and stories, though unicorns are also supposed to be symbolic of pure, chaste, and/or marital love as well as strength and inability to be conquered or tamed. (Check up on why the Scots love the unicorn so much as a symbol—I assure you it has nothing to do with being 'attracted to virgins'.) Also, considering the link to Rome, this one seemed as good a place as any to start.
It all started with one of Reborn's ridiculous ideas of a training trip, specifically when he dropped Tsuna and his Reborn-student senpai Dino on the Japanese version of the Vongola's Death Mountain.
Exasperation at Dino's utter uselessness without his men aside, Tsuna found himself oddly unconcerned. He'd never been out in nature like this—well, 'nature' being a relative term, as Reborn had littered the area with traps and non-native (and some supposedly non-existent) creatures. When the giant scorpions showed up, he was irritated and mildly disgusted, but not particularly worried.
They scuttled around, but gave Tsuna wide berth and when he glared and snapped "Hey!" as they headed for Dino, they decided to leave the Cavallone Don alone, too.
That left Dino blinking at him in something like shock, but the even larger spiders that showed up right afterwards stopped any questions.
Those brought a sense of unease as well as disgust, and Tsuna kicked a half-meter arachnid away from him and wished the ones with the stinging tails* were back. There were too many of the spiders, and they were leaving trails of thin-but-strong silk of varying levels of stickiness that had him stumbling and Dino stuck to the ground the first time he fell.
Tsuna snarled, but didn't have much chance against the swarm and while he was sure that Reborn was somewhere nearby, he couldn't tell where. He felt several bite him, and stumbled to his knees.
Then there was a trumpeting bellow, a cross between an elk's bugle and a horse's neigh, and something large and white thundered into the clearing, crushing oversized spiders under flashing hooves and stabbing at them with a glowing, pearlescent horn.
His first thought was that unicorns were shaped more like deer than anything. His second was to wonder who the hell thought they were quiet, gentle creatures, because even he knew that horses were dangerous by size alone. Deer, goats, cattle—anything with horns or antlers—had head-weapons that were less for attack than defense. Generally sweeping out to the sides to cover more area and block attacks while sometimes inflicting damage in return was one thing. That single straight horn in the center of the creature's forehead was something else entirely.
There was no reason for such a horn but to attack.
Unicorns were very obviously, he thought as the pale shape of grace and fury speared a leaping spider straight through, not passive creatures.
They might be vegetarian, but they were certainly not passive. Fierce, wild, and unrelenting seemed more accurate.
Those few spiders that remained scattered, and the unicorn snorted sharply, snapping its head to the side to make the impaled arachnid fly off its horn. It was a beautiful creature, milky-light hide shimmering and delicate deer-form accented by eyes of a deep, deep shine. They whirled through shades of green-flecked brown like leaves and earth and wild things, and its horn was nearly a meter long, translucent silver and lit from within.
A flare of something, and the horn was clean, the smear of spider-blood burned away, and the unicorn moved over to him, its hooves making no sound despite the thunder of warning they'd given moments before. It—she—dropped her head to nuzzle Tsuna gently, lipping at a bite on his shoulder before stamping a bell-sound and backing up to lower her horn.
Tsuna did not move, dizzy and feeling weirdly unthreatened, and Dino cried out in alarm as the spiral horn touched Tsuna's chest, right over his heart.
He didn't feel any of Dino's worry even when she pushed forward sharply, her horn sliding into his chest without causing pain. He heard the crack of a gunshot (Leon, he was sure) and there was a flare of light and a sharp ping as the bullet was deflected away.
He gasped when a pulse of heat swept through him, and then something inside him was splintering, breaking, shattering apart. The flare of agony came sharp and unexpected, and he managed a single, ragged cry before another pulse of heat drove it away, then the unicorn stepped back, the horn-tip which had been the only thing holding him semi-upright tugging out of his heart.
He crumpled forward, barely conscious, and he heard a shout that sounded like Reborn mingling with Dino's.
The unicorn vanished in a flicker of white, and Tsuna gave in and passed out.
Reborn was a bit taken aback when a unicorn tore into the clearing in a blur of flashing hooves and horn, crushing and kicking and spearing spiders left and right. When the still-living spiders fled, the supposedly mythological creature turned its attention on Tsuna.
He shifted his aim with sniper-rifle-Leon, sighting on the apparently not-myth animal, but when it only nosed at his student curiously before stepping back, he let his guard down.
That was a mistake. Within the moment it took to re-aim, the beast had lowered its head and shoved its horn through Tsuna's chest (heart, Reborn knew where the strike landed but couldn't help but pray otherwise), and Reborn's shot came too late. Didn't hit anyway, a gold-white flash deflecting the bullet—and it pulled back and bolted, leaving Tsuna to crumple face-first on the ground while Dino screamed his little brother's name even as Reborn involuntarily did the same.
Dino was struggling against spider-silk and Reborn made it to Tsuna's fallen form first. He could feel his students' Flames flickering, two Skies, which meant Tsuna was still alive.
He checked for a pulse and paused, surprised to find it strong and steady, then rolled Tsuna onto his back.
He was unconscious—not surprising—but despite the tear in his shirt and the new roundish silver mark above his heart, he was uninjured. Even the spider bites Reborn had seen him receive were gone. Reborn sat back, more relieved than he wanted to admit, and said, "Interesting."
Apparently that settled his worry-radiating other student enough to speak, as he finished tearing free of spider webbing. "Reborn?"
"He's fine," Reborn informed. "I think it healed him." To what extent, Reborn wasn't certain, but it was quite clear that Tsuna was uninjured.
A shaky breath, "Okay. Um. So… we were just helped by a—a—a…"
"Unicorn," Reborn supplied, as Dino seemed unable, a little stunned himself but unwilling to let it show. "It helped Tsuna, at least. It barely seemed to notice you."
He was starting to think that Tsuna had something in him that either boosted or flat-out transcended Sky Flames' effect.
Then Tsuna's eyes opened, burning a bright, steady sunset.
Reborn inhaled sharply, suddenly aware of what the unicorn had done. Without the bullets, Tsuna shouldn't have been able to access his Flames with Nono's seal in place—could not have, not even if desperate or truly dying. (And that seal likely had something to do with how useless Tsuna tended to be, locking away so much of what he was. Maybe when it was gone—but, that was it, wasn't it? With his eyes burning bright with Sky, Tsuna's seal was gone.)
Tsuna blinked once, twice, then sat up with a mild wince, "Well," he mused. "I haven't felt so clear since I was five and that old man poked me in the forehead with a flaming finger."
And that settled it. Tsuna remembered being sealed, remembered being different before he was sealed, and suddenly felt 'clear'. The seal was gone. Reborn was pretty sure that was entirely unprecedented, but it was also a relief. The cracks each bullet put in that seal would not have been enough to break it for at least another year, perhaps even longer—this was a jump-start, and suddenly he could really start to train the Vongola Heir.
Tsuna glared at him, "You know something."
… and Tsuna's before-fledgling and mostly sealed Intuition was apparently on at full. Lovely. That was going to make springing things on his student so much harder.
Those eyes sharpened.
Reborn found himself answering without having consciously decided to do so, "Iemitsu had the Nono seal your Flames on your fifth birthday because you'd Activated so young."
Tsuna frowned and Dino cursed, "Didn't they know what doing that to an Active Sky would do?"
Reborn grimaced, "I hope not. Nono probably didn't, at least; he's sealed other flame-types with no serious ill effects."
"Other flame-types aren't Skies," Dino snapped, sounding appalled. "The Harmonization factor links in with everything! Taking that away could completely destroy someone—Tsuna's lucky it didn't kill him!"
And Reborn knew that, which was part of why he pushed Tsuna so hard, no matter how strange that sounded. Pressure from within mixed with intermittent pressure from without would have increased the rate of degradation of the seal. He'd been hoping to get it to break sooner. That unicorn (and seriously? Unicorn?) had likely just righted nearly everything that had been wrong with Tsuna, at least physically. All the enforced limitations on body and brain would be shattered, and the fact that he wasn't screaming in agony or still unconscious meant it had also smoothed away the damage from forcing the seal off so rapidly. Sure, he'd still be behind his classmates in how much he knew, but with his brain able to retain the information more easily, it shouldn't end up being that hard to help him catch up. His attention span and balance would probably improve, too.
Tsuna stood, far more smoothly than usual as the gold in his eyes dimmed to flecks of amber in brown. "Hey, Reborn… thanks for trying."
Reborn grimaced, "Damn it, that's already annoying."
Tsuna grinned back at him, "If you get to read my mind, I get to read yours."
Reborn huffed and hopped up to sit on his head, tolerating the steadying palm as Tsuna offered Dino a hand up. "Thanks, Dino," he added, and Reborn glanced at his first student to see what Tsuna was replying to, only slightly put out that the surprise had already washed away the evidence of what he'd been thinking moments before.
Dino grinned back as the surprise eased, "So. Unicorn, little bro?"
The implication wasn't lost and Tsuna swatted at him while Reborn laughed. It was relief, mostly, and a little hope.
Tsuna would be just fine.
(The unicorn took to showing up from time to time when Tsuna was at the shrine or in the woods. Reborn decided he didn't want to know.)
*Spiders are the most commonly known, but scorpions are arachnids as well.