Shellshocked, Naruto reached out to Sakura, intent on carrying her into the sea, no matter how badly he got burnt in the process.
"…Don't… come near…!" spat Sakura, fighting through the excruciating pain to raise her head at him. "Water… won't work…!"
To Sakura's knowledge, there were only three ways to extinguish the black blaze produced by the Amaterasu. The first was for the caster to forcibly end the Jutsu, the second was to seal it away using Fūinjutsu, but the third… was to wait for the black flames to turn their target to ashes.
The Amaterasu was truly a fearsome Ninjutsu, as its caster only needed a glimpse of their target in order to set them alight. Countermeasures against it were few and far between, but they did exist— for instance, stealth, extreme speed, and chakra cloaks. Stealth and speed would prevent the Uchiha from focusing their gaze long enough on their target to excite their molecules, and the black flames would have to burn through the chakra cloak before reaching the vulnerable flesh beneath.
And as it happened, Naruto selected the third option.
"Naruto, what are you doing?" gasped Ino. "The flames will spread to you!"
Bubbling orange chakra started seeping out of his pores, shrouding his entire body in Tailed Beast chakra. Protected by the Nine Tails' power, Naruto stooped down and lifted Sakura into a princess carry— unfazed by the black flames licking at his body— before throwing her into the sea.
Perhaps even the Nine-Tailed Fox feared these all-consuming eternal flames— or perhaps Naruto, distressed by Sakura's condition, had instinctually loosened his own Eight Trigrams Seal. Either way, Sakura would never know the truth.
"It's useless," said Nanashi loftily. "Your friend told you the truth."
A pang of guilt stabbed at Nanashi's heart.
Fearing getting outnumbered, she'd used the Amaterasu to quickly but painfully incapacitate the pink haired girl, but her teammates weren't as dangerous as she'd initially thought. She could have easily mowed them all down in a humane manner, instead of wasting her valuable and limited pupil power on death via immolation…
Still, it was rather strange that the pink-haired girl hadn't been consumed by the black flames yet… was she somehow resisting them, just like she had resisted the Sharingan Genjutsu?
"No, no, no…" muttered Naruto, staring vacantly at the black flames continuing to burn underwater. "This can't be happening, Sakura-chan…"
A first tail sprouted from his butt, followed by a second, and then a third… And with the fourth, Naruto finally lost consciousness, surrendering control of his body to the evil within…
"What's happening to him!?" Ino choked out in fear, taking a few steps back. "Is that still Naruto…?"
The wind surged around Naruto, whipping into a furious spiral that sent stones skittering outwards.
Ino could barely breathe with the sheer volume of oppressive Tailed Beast chakra permeating the atmosphere, a chakra so dense that it could be seen with the naked eye. There was so much of it that it was actually displacing the air on its own!
"Shanna-blub-ro!" Sakura gurgled underwater, a column of bubbles surging from her mouth.
In an instant, she had done something that could not be seen with the naked eye, quenching the black flames that had taken root in her body!
She'd managed to resist so far by steadily releasing chakra through her 361 Tenketsu, basically using the Eight Trigrams Palms Revolving Heaven without spinning to simulate a chakra cloak. As a result, instead of consuming her flesh, the Amaterasu had been forced to feed on the chakra leaking through her skin… but that had only been a temporary measure.
With the pain momentarily dulled, Sakura recalled what she had learned about electromagnetism while studying the S-rank Lorentz Gun Ninjutsu— and how Kurosuki Raiga had used his Kiba blades to cancel out her Great Fireball Jutsu, just a few months earlier.
Betting that the Amaterasu's black flames contained ionized particles like ordinary fire, Sakura had dropped her chakra 'cloak' in an instant and generated an electric field with herself at its centre. The gamble ended up paying off— the electric field effectively pulled apart and killed the black flames eating at her body!
With the help of the twin flotation devices on her chest, Sakura began swimming up to the surface, ignoring the sting of saltwater against the swathe of melted skin across her back.
But the moment she surfaced, she was met with a scene ripped straight from the depths of hell— the gravel beach shattered and covered in holes and claw marks, black flames burning everywhere.
Naruto had skipped straight from no tails to four tails in his Demon Fox Cloak Mode, turning into a red, fox-shaped mass of pure malice, while Nanashi had summoned a golden Susanoo to protect herself. But from the looks of it, the incomplete Susanoo wouldn't last for much longer, as Naruto was gleefully ripping out its ribs one by one with his prehensile tails!
One rib… Two ribs… Three, four, five, six, seven, eight!
"Genjutsu: Sharingan!"
In a desperate bid to stop Naruto from tearing apart her weakening Susanoo, Nanashi attempted to drag Naruto and the Nine-Tailed Fox into a Genjutsu— taking advantage of the Sharingan's administrator privileges over Tailed Beasts to bypass the Genjutsu resilience Jinchūriki possessed, when they cooperated with their furry friends!
Naruto froze; his claws clad in evil chakra stopping just short of tearing out her throat.
Sensing an opportunity to strike, Sakura took a deep breath, her fingers rapidly weaving and interlocking with each other.
"Fire Style: Great Fireball Jutsu!"
Sakura breathed out, releasing a massive cone of azure fire from her mouth!
'Payback time!' cheered Inner Sakura, as the flames shot towards Nanashi. 'See how it feels to be a well-done steak!'
Exhausted from the consecutive use of high-level Mangekyō Sharingan techniques, Nanashi's concentration faltered when she felt the searing heat of Sakura's 3000-degree Celsius flames licking at her Susanoo.
Freed from the Genjutsu trapping him, Naruto took a massive swipe at Nanashi, sending the Susanoo along with its passenger skipping across the sea like a stone— while Sakura's fireball sailed harmlessly past them, raising a dense column of hissing steam where it fell in the sea.
Eventually, the Susanoo came to a halt— its form turned translucent, as if it had been nothing but a mere mirage— and then it vanished completely, dropping Nanashi into the sea.
"Go fetch, Naruto!" Sakura shouted, but it was too late.
A mermaid-like figure hopped out of the sea and caught Nanashi as she fell. Shen then performed a graceful flip in midair, before plunging back into the water without even producing so much as a splash or a ripple.
"…Wat," said Sakura, at a loss for words.