"What the hell? Idiot Kensei actually used Bankai?"
The first to arrive was naturally the fastest one—Hiyori Sarugaki? No, first is Mashiro Kuna. She flashed to Shinji's side with Shunpo and immediately started complaining.
"Baldy, is it an enemy?"
The rude one was the yellow-haired girl with a childlike appearance, Hiyori Sarugaki. She already had a hand on the Zanpakutō at her back, ready to jump in and support Kensei Muguruma at any moment.
"Hiyori, Hirako hasn't moved yet."
That was Lisa Yadōmaru, the calm braid-wearing woman in a sailor uniform.
One glance was enough for her to tell that Shinji was still just watching the show.
"Using violence on a child is hardly gentlemanly."
The one making that remark was the blond man with the elaborate wavy hair and aristocratic bearing, Rōjūrō "Rose" Otoribashi.
"Rose, that level of spiritual pressure isn't coming from any ordinary kid."
The one answering was Love Aikawa, the man in a tracksuit with an afro.
"Long time no see, Tessai-sama."
The one who stood out from the others in an entirely different way was Hachigen Ushōda. Back in Soul Society, he had been the Vice Chief of the Kidō Corps, so the moment he saw the former Chief, Tessai Tsukabishi, he greeted him first.
The focus returned to Kensei.
After releasing Bankai, he now wielded a pair of serrated knuckle-blades, one in each hand. Gray caterpillar-track-like armor wrapped around his arms, extending all the way to his shoulders and connecting behind his back like streamers. Bulky armor protruded from his back as well.
This was Kensei Muguruma's Bankai:
Tekken Tachikaze.
"Hm. Now you're finally worth about one Kensei, I guess."
Kensei's ear twitched.
He'd caught Tsuna muttering to himself. Even if he couldn't understand what "one Kensei" meant, he could tell from the tone alone that it wasn't anything flattering. Combined with Tsuna's earlier talk about Hollowfication, every word this brat said felt like it was dancing directly on his nerves.
"Kid, don't die!"
Even so, Kensei still gave him that one warning out of basic decency.
Then he vanished with Shunpo and appeared in front of Tsuna in an instant, driving a punch straight at Tsuna's abdomen. One punch—that was all he needed to put this arrogant brat down, and Kensei had that much confidence.
Kensei's Bankai, Tekken Tachikaze, could inject explosive force into the enemy's body like a raging gale. As long as he wanted, that bursting power could keep pouring in through his fists, dealing internal detonation damage.
In other words, Kensei was fully confident that one punch could tear up Tsuna's internal organs.
Ordinarily, a Bankai that dangerous should never have been used on someone who wasn't clearly an enemy.
But Tsuna had been provoking him nonstop.
Among the onlookers, the same thought surfaced more or less at once:
This is bad.
Even Hiyori shut her eyes, unwilling to watch the outsider—who was about the same size as she was—get blown apart.
Hachigen had already begun preparing Kaidō in case he had to save him.
Of everyone there, only Tessai remained calm.
He was one of the few people who had already seen Sawada Tsunayoshi's true power.
Tsuna had mastered Bankai long ago.
Just as Kensei's iron fist was about to strike Tsuna—
a calm voice reached his ears.
"Bankai."
"Destroy adversity, illuminate the earth—Taiyo…"
Brilliant yellow Sun Flames exploded outward the moment Bankai was released, instantly swallowing both Tsuna and Kensei in light.
Inside that blaze, Kensei's fist was stopped by a red boxing glove.
Kensei looked up.
After releasing Bankai, Tsuna had changed again. The red full-cover boxing gloves drew the eye first, but that was not all. Golden armor guards had appeared on his forearms, lower legs, and forehead. Under the violent pressure of the flames, the upper half of his Shihakushō had been blown away, revealing a lean, well-trained torso.
What Kensei didn't notice was the bracelet on Tsuna's left arm:
A wrist device lined with ten small torch-shaped rings, with the Vongola VG emblem at its center.
This was Tsuna's Sun-attribute Bankai:
Vongola Gear – Sun Bracelet Ver. X.
"Now that's more like it—a Bankai!"
Far from being disappointed that his punch had been blocked, Kensei burst out laughing.
Tsuna's form after Bankai looked exactly like a modern boxer from the World of the Living.
That made him a fitting opponent for Tekken Tachikaze.
Kensei shifted one step back to gather power, then launched into a storm of punches with both fists. Tsuna answered in kind, his own fists moving just as quickly, colliding head-on with Kensei's iron fists.
The faster they fought, the more Kensei realized that he was starting to fall behind Tsuna's speed.
This was one of Tsuna's Bankai abilities:
The super-activation of the Sun Flame.
A body driven into ultra-activity could unleash terrifying strength and speed.
This was the Extreme Combination Punches.
Kensei had no idea what Tsuna's Bankai really did, but he forced himself to keep up anyway. Whenever he couldn't match a blow, he used the treads around his forearms to block instead. Even while taking hits, Kensei still had the nerve to taunt Tsuna.
"Give it up, kid! Your fists can't possibly hit harder than mine!"
Just as Tsuna was about to answer back, a surge of blood rose in his stomach. He forcibly suppressed the pain inside his body, but a thread of blood still escaped from the corner of his mouth.
"Brat, my Tekken Tachikaze stores explosive force inside your body. I've already packed you full of more than enough power to blow you apart any time I want!"
Kensei roared,
"You've already lost, kid!"
Tsuna forced down the pain in his gut and shot back,
"You people really do love sharing all your information with the enemy, huh?"
"Kid!"
That answer wiped the grin off Kensei's face.
"In that case, I'll finish this with one punch!"
At this point Kensei was completely fired up. He had forgotten all about not wanting to use Bankai too recklessly. Right now, all he wanted was to defeat Tsuna with one full-force blow.
He powered through Tsuna's rain-like barrage of punches and drove one heavy strike straight into Tsuna's abdomen.
The instant his fist connected, Kensei detonated all the explosive force that had been stored inside Tsuna's body.
BOOM!
Violent spiritual pressure exploded from inside Tsuna's body.
In front of everyone's stunned eyes, Tsuna was blasted clean through.
Blood sprayed in great sheets from his body, and a hole the size of a dinner plate opened in his abdomen.
"This is bad—Hachi, save him!"
Shinji reacted immediately, barking orders to the Visored. "Rose, get Kensei away from him!"
"That bald idiot went way too far!"
Hiyori grabbed one of her sandals and charged forward, fully intending to knock some sense into Kensei while he was still drunk on the fight.
"Idiot, he's dead."
Mashiro's complaint came just as quickly, but her body was already moving. She was ready to send Kensei flying with one of her kicks.
Unlike Hiyori and Mashiro, the others were in no mood for quips in an emergency.
They all moved at once.
"Please wait. The fight isn't over yet."
The one who stopped the Visored was, unexpectedly, Tessai Tsukabishi, who had come here with Tsuna.
"Tessai, if we wait any longer, that kid's going to bleed out!"
Shinji sounded openly irritated. If Tsuna hadn't identified him by name so clearly before, Shinji wouldn't have cared at all whether he lived or died.
Over the course of the fight, Shinji had already figured something out.
If it had really been Urahara who told Tsuna about him, Tsuna would never have reversed his name like that. That was Shinji's own personal quirk. Urahara had no reason to pass on information that detailed, and that useless.
That was why Shinji had decided to save him—
only to be stopped by Tessai instead.
Tessai offered no further explanation.
The reason he stopped the Visored was simple:
He didn't want them getting caught in Tsuna's next move.
His eyes were fixed on Tsuna's blazing bracelet, which now shone like a miniature sun.
All ten torches on it were lit.
Back when Tsuna had trained Bankai, he had deliberately found excuses to get himself injured, all so he could unleash an attack no one expected.
"So what? Are you done already?"
Kensei spoke harshly, but inwardly he had begun to regret it a little. He had hit too hard. A hole you could see the scenery through was a grievous wound on anyone.
"Defend."
Kensei honestly thought he must have heard wrong.
This badly wounded brat was telling him to defend?
What kind of joke was that?
Just as Kensei was about to snap back, he suddenly felt an enormous pressure gathering on the body of the heavily wounded boy in front of him—
No, more accurately, on Tsuna's fist.
That tiny fist was concentrating an absurd amount of spiritual pressure.
Just how monstrous was the attack about to come out of it?
Kensei had no time to think.
Blazing light instantly wrapped around Tsuna's right fist, and his boxing glove shone like the sun itself.
Defend?
How was he supposed to defend against this?
Kensei only barely had time to cross both arms in front of his chest before Tsuna's fist landed on his forearms. Within the violent burst of spiritual pressure, two crisp cracking sounds could be heard.
Sunshine Counter.
All of that terrifying pressure Kensei had sensed hit him head-on.
There was no blocking it.
Kensei was blasted away by that dazzling fire, pushed so far and so fast that he vanished from sight in an instant.
BOOM!!!
Far off in the depths of the warehouse, violent reverberations rang out one after another.
Hachigen's expression changed immediately.
The barrier he had placed around this area—
had actually been damaged.
Hachigen hurriedly formed hand signs to begin repairing it with barrier Kidō, only to realize someone had moved even faster than he had.
Tessai.
The moment he saw Tsuna's fully lit sun-bracelet, he had already prepared himself.
With Tessai's barrier Kidō layered over it, the shaking of the warehouse finally subsided.
Hachigen let out a breath of relief.
For some reason, he had the strange feeling that Tessai had come here for the sole purpose of reinforcing the barrier.
Seeing that the fight had finally ended, Shinji used Shunpo to appear right in front of Tsuna.
"Kid, wasn't that a bit much? That kind of mutual-destruction ending could obviously have been avoided."
"Mutual destruction?"
Tsuna straightened his back and lifted his chin, smiling brightly. "I'm not sure I know what you mean."
Shinji stared in disbelief at what he was seeing.
The giant hole in Tsuna's abdomen—
had disappeared.
White steam was rising from his stomach. That terrible perforating wound had already sealed shut, and it looked like it would fully heal before long.
In other words, there had never been any mutual destruction at all.
Sawada Tsunayoshi had regenerative ability.
The only one who had truly taken damage was Kensei Muguruma, who had tanked Tsuna's attack head-on and possessed no such recovery.
---
Author's Note:
Ryohei's Sun Bracelet in canon is honestly a bit too abstract for me. It's understandable for "trading blood for energy," but having to nearly kill yourself first just to unleash a big move makes no sense—especially when it uses the Sun Flame, the only VG flame in the whole series with healing properties, yet somehow can't heal its own user.
So in this story, the Sun Bracelet is changed so that it does have restorative abilities. Once the protagonist uses Sun-attribute Bankai, he becomes something like a berserker—able to trade health for output, but also recover his own injuries.
Another changed is the torch-lighting mechanic of the bracelet. Instead of only counting the number of times the user gets injured, it now scales according to the severity of the damage, lighting the torches to different degrees.