The dawn mist still clung to the trees in the secluded training ground behind the Uchiha district. It was a restricted area, usually reserved for the elite, but today it was occupied by a single family.
Kaori stood at the edge of the clearing, her hands weaving signs. A faint, shimmering barrier erected itself around the perimeter—a sensory disruption barrier.
"The barrier is up," she announced, dusting off her hands. "No one can see or sense what happens inside."
Satoshi stood in the center of the field, drawing his katana. The blade was a standard issue ninjatō, straight and efficient.
"Draw your weapon, Ren," Satoshi commanded.
Ren pulled the sword from the scabbard. It felt heavy. While he had the memories of a Chūnin, his body was still getting used to the "awakened" state.
"We have three goals today," Satoshi listed. "First, Kenjutsu. Second, Ninjutsu development. Third... the Eyes."
He assumed a stance.
"Let's start. Come at me."
Ren lunged.
Clang!
Their blades met. Ren felt the shockwave travel up his arm. Satoshi's lightning wasn't just for show; it vibrated at a high frequency, numbing Ren's grip instantly.
"Too slow," Satoshi said, kicking Ren in the gut.
Ren stumbled back, wheezing.
"You have the three-tomoe Sharingan active. You can see the kick. Why couldn't you dodge?"
"I saw it," Ren gasped. "But I didn't know which way you would follow up."
"Predictability is death," Satoshi said. "Now... show us the Mangekyō. If we are going to the front lines, we need to know your limits."
The atmosphere instantly grew heavy.
Ren closed his eyes. He dug deep into the dark, cold reservoir of chakra in his brain.
He opened them.
The world turned red. The three tomoe spun and merged, forming the three-arow pointing outwards pattern. Blood immediately trickled from his eyes.
"What are they?" Satoshi asked, stepping back cautiously.
Ren focused on his Left Eye. This one felt heavy, like burning oil.
"Amaterasu (Goddess of the Sun)," Ren whispered.
He focused his gaze on a large granite boulder at the edge of the field.
FWOOSH.
Black flames exploded into existence on the rock. They weren't orange or red. They were jet black, undulating like liquid darkness. The heat was instantaneous and oppressive. The rock didn't just heat up; it began to crumble into nothingness.
"Inextinguishable Flame," Ren explained, clutching his bleeding left eye. "It burns until the target is ash. Water won't put it out. Rolling won't put it out. It is absolute destruction."
Satoshi stared at the black fire with dread. "A flame that eats rock... frightening. And the Right?"
Ren focused on his Right Eye.
The pain was different here. It wasn't a burn; it was a freeze. His mind suddenly felt like it had expanded, processing information at a speed that made the world seem to stand still.
"Omoikane (God of Wisdom)," Ren stated.
He looked at his father.
To a normal Sharingan, Satoshi looked like a man with strong chakra. To Omoikane, Satoshi was a dataset.
Ren saw everything. He saw the microscopic twitch in Satoshi's calf muscle indicating a lunge. He saw the flow of chakra in Satoshi's meridian points, calculating the exact millisecond it would take to mold a Fireball Jutsu (0.4 seconds). He saw the wind resistance around his sword. He saw the "simulation" of the next ten seconds of combat playing out in his mind like a branching tree diagram.
"It's not just analysis," Ren explained, his voice sounding robotic and detached. "It is Comprehensive Computation. I can deconstruct reality."
He looked at the black flames of Amaterasu.
"The flame temperature is 3,000 degrees. It is consuming the oxygen in a 5-meter radius. If I throw a kunai at an angle of 34 degrees, the updraft will carry it exactly into the center."
He looked at his own hand, where he had failed to form the Chidori earlier.
"And I know why my Chidori failed."
Ren held out his hand again. Omoikane overlaid a blueprint on reality. He didn't just "try" to mold chakra; he followed the instructions his eye was giving him.
Compress chakra to density 8. Increase vibration frequency by 200%. Shield the skin with a 1mm layer of Yang chakra.
CHIRP-CHIRP-CHIRP!
Instantly, a perfect, blindingly blue ball of lightning formed in his hand. It was stable. It was loud. It was lethal.
"You mastered it?" Satoshi gasped. "In one try?"
"I didn't master it," Ren said, dispelling the lightning and falling to his knees as the eye deactivated. "I solved it. Omoikane allows me to see the 'source code' of any jutsu or physical phenomenon. If I see it, I understand it. If I understand it, I can perfect it."
Kaori rushed forward to heal his bleeding eyes. "Amaterasu to destroy the enemy. Omoikane to understand the world. You have become the ultimate tactician."
"But the drain..." Ren panted, his head pounding. "Omoikane burns mental energy. Amaterasu burns physical chakra. I can only use Omoikane for maybe two minutes before I pass out."
Satoshi sheathed his sword, a look of fierce pride on his face.
"Two minutes is enough. In a ninja battle, death happens in a split second."
He looked at the lingering black flames.
"With Omoikane, you can perfect your Ninjutsu theories before we even leave the village. You will enter the war not as a rookie, but as a master of efficiency."
Satoshi extended a hand to pull Ren up.
"Get up. Use your eye technique to analyze my sword style. Let's see if you can find a flaw in your father's defense."
Ren grinned, wiping the blood from his cheek.
"I already found three."