Rei's Mangekyo

"How could it be him?"

Uchiha Rei stood in the shadows, his gaze sharp as a blade as he stared at the figure gradually making his way into Orochimaru's laboratory. In Konoha, three people were connected to Orochimaru: Anko Mitarashi, Danzo, and Kabuto Yakushi. But the person entering Orochimaru's training lab wasn't any of them. He was a member of the Uchiha Clan.

Uchiha Rekka, an Elite Jonin of the Uchiha Clan, was hailed as the strongest after Itachi. His arrival couldn't be a mere coincidence.

"The Shadow War between the Hokage's leadership and the Uchiha is just a public excuse. Their real opponents are the Hokage's leadership and Akatsuki."

The two strongest members of the Uchiha Clan were both lackeys of the Third Hokage and Danzo. What chance did the Uchiha have against the Hokage's leadership?

Rei sighed inwardly. He knew he'd reported Itachi's information yesterday. This Rekka had almost certainly been sent by the clan to silence him.

"If that's the case, I'd better strike first."

His left eye twitched faintly. An uneasy vortex swirled in his dark iris: the Mangekyo Sharingan he'd just obtained through the Sign-in System.

"Where is that Uchiha Rei?" Rekka asked coldly, anger in his voice. "How dare he betray Lord Itachi? I'll show him the power of the Three-Tomoe Sharingan."

Before he'd even finished speaking, something whistled through the darkness.

"Shik—shik—shik—"

Three Kunai flew in from different angles, precise and deadly, cutting off every avenue of escape. Rekka's pupils shrank. He sprang aside, avoiding a fatal blow, but one Kunai sliced a gash in the armor on his shoulder.

"An enemy!"

Rekka reacted instantly, gritting his teeth as he formed Hand Seals.

"Fire Style: Great Fireball Technique!"

Boom!

Flames roared like a dragon, carrying a wave of scorching heat as they surged into the darkness. But amid the blaze, a figure raised one hand and formed Hand Seals so quickly they were almost impossible to see—

"Fire Style: Great Fireball Technique!"

Another, even more intense fireball burst forth. It swallowed Rekka's attack and kept coming with its remaining force, scorching a trail across the ground. As the flames flickered, Rekka's expression finally changed.

"His Ninjutsu is stronger than mine..."

With no time to think, he drew his sword and charged. The blade gleamed coldly as it thrust straight for his opponent's throat.

But his opponent merely raised a Kunai to deflect the strike, then followed up with a kick that crashed forward with terrifying force.

"Thud!"

Rekka flew backward like a kite with its string cut and slammed into the wall. Blood sprayed from his mouth, and cracks appeared across the armor on his chest.

"His Taijutsu is no match for me either..." He was horrified.

He couldn't hold back any longer.

He took a deep breath. The Three-Tomoe in his Sharingan began spinning rapidly, and a faint power beyond reality emerged.

"Hell Viewing Technique."

In an instant, the lights in the training lab began to twist eerily. The walls seemed to spin as space warped, stretched, and overlapped. A cold smile touched Rekka's lips. "You've fallen for my Genjutsu. No matter how strong you are, you won't be able to break free."

His eyes brimmed with confidence. According to the clan's intelligence, Uchiha Rei's ocular power was extremely weak. He couldn't resist a high-level Genjutsu cast with the Three-Tomoe Sharingan.

But the next second, his vision suddenly blurred.

When he opened his eyes again, he was standing on the Uchiha Clan's training grounds.

Familiar wooden posts and targets surrounded him. In the distance stood the clan's main residence and a path of blue-gray bricks. Everything looked just as it did on an ordinary afternoon during training.

"This is... a Genjutsu? No... this isn't my Genjutsu!"

Horrified, he spun around. In the center of the training grounds, flames spread silently, like countless flickering tongues. They began creeping closer.

"Hiss—!"

Rekka's pupils contracted violently. The flames weren't ordinary fire. They seemed alive, and in an instant, they clung to his body.

"Aaaaaah!"

Pain! The flames devoured his nerves and will, burning from his skin down to his bones. His scream tore through the sky.

"This can't be... This isn't just an illusion... I... I'm really burning... Why can't my Sharingan resist it?!"

In reality, Uchiha Rekka stood with vacant eyes, his body beginning to tremble violently.

In the darkness, Uchiha Rei slowly released his Hand Seals. A line of blood and tears ran from his left eye. The pupils of his Mangekyo spun into a double-ringed spiral, as deep and dark as a vortex of death.

"Magatsuhi."

The name of his Mangekyo left his lips.

"The most realistic Genjutsu doesn't deceive the eyes... It deceives the soul directly."

It was said that every Mangekyo Sharingan embodied an obsession buried deep in its owner's soul.

Uchiha Obito had broken down after witnessing Rin Nohara's death. Unable to face the cruel reality and yearning to escape, he awakened Kamui, which let him warp space and conceal himself. He hid in the void, all to escape his pain.

Uchiha Shisui had spent his life trying to stop the Uchiha Clan's rebellion through peaceful means. His Sharingan's power was called Kotoamatsukami, a silent change that symbolized his bloodless ideal.

Uchiha Itachi had taken the lonely path forced on him by the choice to wipe out his clan. He had poured his understanding of pain into Tsukuyomi, creating an endless cycle of dreams.

Uchiha Madara had wanted to control fate and turn everything around. His Sharingan abilities all strengthened his Susanoo. His powerful Susanoo embodied his resolve to control everything.

And Uchiha Rei, poisoned and with only three days to live, had awakened his Mangekyo in the gap between life and death. It was called Magatsuhi, connecting death and reality and hovering at the boundary between life and death.

It had two abilities. When used against an enemy, it burned ocular power to open the gates of the Yellow Springs and send the target inside, trapping them in a near-death illusion where they experienced true death in their own consciousness. This symbolized death. When used on himself, burning ocular power accelerated the flow of time and granted him a brief period of invincibility. This symbolized life.

No one's Mangekyo was the strongest, but each was undoubtedly the one best suited to its owner.

After dealing with Uchiha Rekka, the clock struck twelve.

[ Ding! ]

[ Sign-in started! ]

[ Sign-in location: Laboratory No. 1 of Orochimaru! ]

[ Sign-in reward: Jonin-level Medical Ninjutsu! ]

A warm current seeped into Uchiha Rei's mind. He felt new memories taking shape, the essentials of various advanced Medical Ninjutsu etched into his mind. He tried to mold chakra, and green Medical Chakra glowed in his palm. He could easily perform the Medical Ninjutsu Chakra Scalpel Technique with precise, pure control—enough to rival Konoha's Elite Medical Ninjas.

This was good news. But it was also bad news.

Jonin-level Medical Ninjutsu could somewhat suppress the poison in his body. But the poison came from Hanzō, the pinnacle of the Ninja World, and his Poisonous Weapon was at Kage Level. Ordinary medical techniques couldn't remove it completely. For now, all Rei could do was slow the poison in his body. Given enough time, he could ease its effects. But on the eve of the Night of the Uchiha Clan Downfall, time was exactly what he lacked.

The good news was that he had only one Mangekyo for now. With just one, he couldn't unlock the Perfect Susanoo. In the future, he would certainly need to transplant a second Mangekyo Sharingan to obtain the legendary ultimate Dojutsu, the Perfect Susanoo. This Medical Ninjutsu would be crucial then.

Rei sorted out his thoughts, put on his Goggles, and left Orochimaru's laboratory. The moment he stepped outside, he sensed an unfamiliar chakra signature. Someone was using the Telescopic Technique to watch him.