It was late, almost dusk, when Shisui appeared on the training ground. The knowing look they shared was all that was needed; it was time to test Itachi's progress.
"Are you sure about this, Itachi?" Shisui asked, adjusting his headband. "More than ever. I want to know how far I've come."
The training ground was blazing under the late afternoon sun. Itachi had already changed a great deal: his body was more defined, stronger from his training with Fugaku. Still, facing Shisui, the difference was obvious. Shisui was taller, broader, with muscles that gave him the air of a complete warrior. That difference in size was noticeable in every movement; each of his strikes carried a force that was difficult to block.
"You've progressed fast, Itachi..." Shisui said, flexing his neck. "But don't forget I'm still your senior."
The fight began with a flurry of shuriken. Itachi raised his magnetic defense, making metallic fragments spin around him to deflect the projectiles. Sparks lit up the air with each impact. Shisui didn't stop; he appeared in a flash in front of him, twisting his body to deliver a powerful roundhouse kick. The size of his leg and the force of the blow sent Itachi flying back several meters, though he managed to roll and recover.
"Your defense works against weapons… but what about this?" Shisui countered, advancing with a storm of blows. Itachi tried to cover himself, but every block hurt; the difference in mass was clear. It was like fighting a moving wall.
Desperate, Itachi channeled chakra into a pressurized air cannon, which exploded in front of Shisui and pushed him back for an instant. However, his rival barely smiled, planting his feet firmly. "Well thought out… but not enough." He filled his lungs with air and launched: "Katon: Gōkakyū no Jutsu!"
A huge fireball ravaged the field, forcing Itachi to use all his ingenuity. Lately, he had been working on a new jutsu, if you could call it that, in which he generated a Gauss cannon with chakra threads. At its center, he released a fireball with metal particles connected by electric threads that formed a kind of network. He condensed energy and fired his new Plasma Cannon Jutsu, which tore through the fire toward Shisui. It could be said that it consumed everything in its path at high speed—a lethal, long-range attack. The fireball was pierced through the center without any resistance. Still, the resulting heat made Itachi's skin redden.
Shisui, meanwhile, was no longer at the end of the tunnel. His close-quarters combat speed was another story. He appeared at Itachi's back, kunai in hand, but Itachi reacted with an electrical spark that briefly paralyzed the air around them, forcing Shisui to retreat.
"Not bad," Shisui admitted, astonished by Itachi's jutsu, which could probably be ranked as S-class.
The combat escalated. Shisui launched an impossible sequence of shuriken in crossing parabolas to test Itachi's metal shield. Itachi's Sharingan shone, catching trajectories and correcting his magnetic defense to create a mobile shield, deflecting projectiles and absorbing the gaps.
"Now!" Itachi thought, and unleashed his most dangerous technique again: the Plasma Cannon Jutsu. A concentrated discharge of electrical chakra and heat shot out in a straight line. The ground sizzled, and a nearby tree was charred. Shisui barely managed to dodge, feeling the heat wave graze his face, but Itachi's reserves were at their lowest limit.
The exchange became fiercer: blows, kicks, kunai clashing. Shisui's Sharingan allowed him to anticipate movements, but Itachi had closed the gap, combining physics and chakra in an unpredictable way. In the end, both were panting. Shisui had managed to place the kunai at Itachi's throat, as he still had more chakra and more strength. Itachi understood that the use of his plasma cannon needed to be more prudent.
The days turned into weeks, and the weeks into months. The training rhythm of Itachi and Renji was constant, but also solitary: Fugaku had left for the front, and the village lived in a state of growing tension.
Under Itachi's guidance, Renji learned to feel the flow of chakra. Though he couldn't mold it with the same ease, his natural affinity for shapes and angles allowed him to invent strange solutions: he designed a wooden boomerang reinforced with simple seals, calculating trajectories and rebounds that surprised even Itachi.
Every night, Itachi worked in his secret notebook of experiments: scribbles of magnetic fields, half-finished equations, and drawings of makeshift mechanisms. His hands, stained with charcoal and metal, were a testament to the fact that he was creating something different, something that he himself had yet to fully comprehend.
His physical training became tougher: running in the rain, practicing taijutsu to exhaustion, and receiving advice from Shisui, who, though he always defeated him, encouraged him to polish every detail.
Despite everything, there was a sense of uncertainty in the air. The war was far away, but its echoes reached the village in the form of rumors: skirmishes, losses, names of clans that returned with fewer children than they had left with.
One evening, while Itachi and Renji were practicing by the river, a messenger arrived at the village. The murmur grew like a fire, and soon the news spread to every corner of Konoha: "The Battle of Kannabi Bridge is over…"
The voice of the elder who announced it was trembling. They had won, yes… but at a terrible cost. Many Konoha ninja would never return. And among the names heard were heroes, comrades, friends of entire families. The echo of that battle would change the course of the war… and their own lives.
Itachi looked up at the horizon, his eyes colder and more mature than befitted his age. He knew that soon, very soon, that same fate of blood and fire would knock on his door.