"Hahaha! Fake! It's all fake!"
"There is no Uchiha Madara in this world! No Sage of the Six Paths! And certainly no Otsutsuki Kaguya!"
Underneath the crimson blood moon, the Fourth Shinobi World War reached its chaotic climax. At the center of the battlefield, Uzumaki Menma stood atop the head of the Black Nine-Tails, letting out a burst of wild, manic laughter as eighty thousand soldiers of the Allied Shinobi Forces surrounded him. Below him, the legendary powerhouses of the shinobi world looked on with grim expressions; over the past two years, they had grown accustomed to this madman who constantly claimed their reality was a lie.
As his laughter subsided, Menma tore the white three-eyed fox mask from his face. He could feel the rhythmic throbbing of his transplanted Sharingan and the overwhelming sense of rejection emanating from the fabric of the world itself.
It had been fifteen years since he first crossed over into this world. As a reincarnator, he originally thought he was Uzumaki Naruto, only to discover he was Uzumaki Menma. In this realm, Minato Namikaze and Kushina Uzumaki were both alive—confirming that he was trapped within the false reality of the "Limited Tsukuyomi."
To find a way out, he had spent over a decade growing stronger. He collected various Kekkei Genkai, mastered forbidden secret techniques, and even transplanted a pair of Three-Tomoe Sharingan into his own eyes. He had subdued the Black Nine-Tails and ascended to the level of a Beyond-Kage rank powerhouse. Yet, no matter how hard he searched, there were no traces or legends of Madara, the Sage of the Six Paths, or Kaguya in this world.
In a final act of defiance, he launched a "Great Spiralling Ring" at each of the Five Great Shinobi Villages, triggering the Fourth Shinobi World War himself. As the world's rejection grew stronger, a white light began to flicker across his body.
"This is my parting gift to this world," Menma muttered.
In his hand, he condensed a sphere of dark purple energy, surrounded by a planetary ring of wind-style chakra. As the Great Spiralling Ring hit the ground, a pillar of white light soared into the sky. The resulting explosion consumed half the battlefield and over ten thousand ninjas. Menma vanished into the light.
————————
The Real World: October 10th, Year 51 of Konoha
In a secret delivery room surrounded by barriers in the forest outside Konoha, Uzumaki Menma slowly opened his eyes.
"As expected of the Yellow Flash... but what will you do next?" a voice whispered nearby.
Menma's eyes widened. He saw a man in a tiger-striped mask holding him in one arm. Turning his head slightly, he saw Minato Namikaze holding another blonde infant in his arms. Nearby, Kushina Uzumaki wailed in pain on a bed.
'The Night of the Nine-Tails?' Menma thought in shock.
'Wait... if Minato is holding Naruto, then who am I?'
Before he could process the situation, the masked man's explosive tags detonated, blasting Minato out of the room. In that instant, Obito pulled both Menma and Kushina into the Kamui dimension.
"Menma!" Kushina cried out, struggling to reach her child, but she was far too weak from the ordeal of childbirth.
Obito bound her with chains and looked down at the infant in his arms.
"Not crying or making a sound?"
A cruel thought crossed Obito's mind. Simply killing the child would be boring; he wanted his former sensei to feel the pain of losing everything. Why not raise this child as a villain to destroy Konoha? The thought of Minato's two sons killing each other years later made Obito smile behind his mask.
However, raising a child himself was too much work. Obito warped to the outskirts of the village, arriving at the orphanage. He placed a Kamui coordinate mark on the baby, left a note with the name 'Menma,' and set him down at the door.
"I'll come back for you in ten years," Obito whispered before vanishing into thin air.
'Hey! At least knock on the door first!' Menma thought, freezing in the cold night air.
Being a newborn with no chakra or mobility, he did the only thing he could: he wailed at the top of his lungs. In the distance, the Nine-Tails was summoned, beginning its violent rampage through the village.
"Matron, why is it so noisy outside? Has something happened?" a young child's voice asked.
The orphanage door creaked open. Nonō Yakushi stepped out, accompanied by a grey-haired boy named Kabuto.
"Oh my!" Nonō exclaimed, picking up the crying baby. She found the note tucked inside the swaddle. "Menma... is that his name?"
Seeing the terrifying silhouette of the Nine-Tails in the distance, Nonō realized the Jinchuriki had lost control. She quickly gathered the children to head for the shelters. It wasn't until the next day that she learned the tragic news: the Fourth Hokage and his wife had fallen in battle.