Underground in the battlefield, a pair of eyes constantly watched the three people above.
'This can't go on. I need to find a way to wake Uchiha Obito!'
Drifting within the soil layer, almost merging with nature, Black Zetsu began to plan.
Just as he was about to put his plan into action, the aura of another observer caught his attention.
It was an aura from a higher existence, something Black Zetsu, a creation of Yin-Yang Release, couldn't resist.
'Mother... no, could it be Mother's clanmate?!'
Almost instinctively, Black Zetsu prepared to use the Mayfly Technique to escape.
But thinking of the convenient tool that was Obito, and the arrangements he had made over a thousand years on the Uchiha, he forcefully halted.
'Take one look, just one look!'
'If things seem hopeless, retreat immediately, preserving the spark for Mother's revival!'
With this thought, Black Zetsu used the Mayfly Technique, quietly swimming toward the direction of the leaked aura.
Then, through the ubiquitous roots and mayfly spores, he sensed an extremely tiny man on the surface.
He wore a white feathered garment, staring intently at Sasuke in the distance, muttering to himself.
"Descendants of that bitch Kaguya... should I test them? Maybe they have the talent to become vessels."
Hearing the other party's words, Black Zetsu immediately burned with anger, though he didn't dare do anything. He could only watch the other party's every move from the side.
"10% Chakra is still sufficient. Should I just try? If successful, wouldn't it be much faster than slowly regenerating using Shibai's remains?"
As he spoke, Black Zetsu saw the man move. His entire body rapidly enlarged as he charged forward.
The next instant, the black rod in his hand shot forth. He had already arrived before Sasuke.
"!"
The first to notice the anomaly was Sakura. As a Space-Time Ninjutsu user, she sensed space warping.
Sasuke and Naruto were completely unaware. Faced with this sneak attack that leaked no aura, they were still concernedly supporting Chiyo and lifting Gaara.
"Dodge!"
Sakura shouted at Sasuke.
Trust built through countless missions over two and a half years made the boy retreat without hesitation upon hearing the girl's cry.
However, the enemy he faced now was one who created, toyed with, controlled, and even surpassed Chakra.
Influenced by an unknown technique, the black rod suddenly elongated, piercing toward Sasuke.
At the critical moment, the light of the Flying Thunder God flashed. The girl's hand grabbed Sasuke, about to whisk him away with a space-time jump.
Yet the enemy, with the ability to manipulate space, had golden light flicker in his eyes. He infinitely magnified the spatial dimensions around them, twisting all space pathways formed by Chakra Connections.
"Damn it!" Sakura gritted her teeth, pulling Sasuke behind her. Haki coiled, forming an intangible armor outside her body.
Boom!
The moment the black rod collided with the Haki armor, a loud crash erupted. Immediately, a violent shockwave surged from where they clashed, raising dust that blocked everyone's vision.
Then, the Haki armor shattered-
As if cut by a high-pressure water jet, smooth as a mirror.
The black rod, carrying the Otsutsuki Clan's unique data backup, the [Kama], pierced through Sakura's abdomen.
"Cough!"
Grabbing the black rod, Sakura coughed up a mouthful of blood. No longer maintaining Life Return, her body swelled, returning to a height of 2.3 meters.
Shadows covered the attacker.
From her palm, she projected a beam of light, manipulating 'entropy', overturning thermodynamics, transforming it into frost, then casually turning the frost back into flame.
The thermal cycle constructed from this gathered into a storm giant sword. Armament Haki and Conqueror's Haki simultaneously coiled around it.
Hakoku: Vacuum Wave!
Having completed the complex and exquisite conversion, the storm sang. Finally, the sword carrying the conqueror's will slashed into the enemy's body.
In the intense tremors, the sneak attacker was crushed by the immense, irresistible force, sent flying like a ragdoll. The earth behind him was also smashed to pieces, finally plunging into an abyss.
"Damn it, just an ordinary human, why would..."
The puzzled voice was swallowed by the storm. The will damage formed by Haki repeatedly eroded and destroyed his cells.
Left with no choice, his resentful eyes glared at the girl standing on the cliff he had just created with his slash. He hastily opened a black portal, escaping in a sorry state.
"Ugh!"
Clutching her abdomen, Sakura knelt on one knee. Black patterns crawled from the wound on her abdomen, soon climbing onto her face. The eyes pierced by the patterns began turning white.
[Notice: Detected alien data intrusion. Emergency purge program initiated. Haki activated. Achievement point consumption started.]
"Sakura!"
In the brief moment of change, when Sasuke and Naruto realized what had happened, the girl had already collapsed in a pool of blood.
The two rushed forward in panic. Observation Haki's aura sensed the girl's life growing weaker under the erosion of a strange force.
"No, don't die!" Sasuke covered Sakura's wound, his eyes filled with remorse.
"Quick, stop the bleeding! Find a way for first aid!"
Naruto pushed Sasuke aside, opening Sakura's ninja tool pouch to search for medical supplies.
"It's me, it's all my fault!"
In extreme self-blame, a stream of cold Yin Release Chakra flowed in Sasuke's brain.
Simultaneously, the tomoes in his eyes spun faster and faster. Finally, under the rampage of emotions, they completed fusion, outlining a crimson hexagram interwoven with black lines.
"I refuse to let such a future happen!"
The power of the Mangekyo was born. Sasuke almost instinctively understood how to use this power.
Blood flowed from his eye sockets. Incredible Yin Release slowly modified this reality he deemed unfavorable.
Mangekyo: Toyokumono-no-Mikoto!
Intangible adjustments spread, gently plucking the strings of fate, briefly plunging the course of all things here into chaos.
Then, using another power to govern everything amidst the chaotic state, weaving the order the caster needed!
Mangekyo: Ame no Tokotachi!
[Detected external assistance. Alien data activity decreased. Purge program failed. Switching to alternate plan. Oni blood activated. Fusion and assimilation started! 1%, 2%, 3%, 4%, 5%...]
In the deathly silence, the sound of a surging torrent suddenly erupted. Sakura was instantly engulfed by countless gloomy and cold auras, frozen stiff, her consciousness barely able to function.
Innumerable memories of Oni deaths converged, continuously emerging from her consciousness, pulling her gradually closer to that non-human boundary.
"What?"
Naruto was about to start bandaging when he saw Sakura's black patterns begin fading, turning white. Simultaneously, a silver-white horn grew from her forehead.
Grey water vapor condensed out of thin air, turning into a rainstorm. Thunder flashed in the sky, as if the entire world pulsed with the girl's breathing.
"Damn it, it hurts so much—!"
Sakura felt herself burning. Along with her, the surrounding world also boiled.
Shaking the world, operating endless mighty power, the Oni's roar attracted infinite lightning. Intense light and heat suddenly burst forth, turning the earth into a sea of thunder.
Threads of lightning as fine as silk raced across the ground, instantly extending for thousands of miles, fiercely striking the last bystander present.
Amidst a stretch of furious pure white lightning, Black Zetsu, who had gone to great lengths to attach himself to Obito, hopelessly closed his eyes.
'Damn, I wasn't the one who ambushed you!'