The nights after Amanai's first lesson settled into a routine. Amanai arrived after sunset, drilled Muzan for several hours, then left before dawn. The training covered shuriken accuracy, kunai grip, basic taijutsu strikes. All of it was physical. None of it was ninjutsu.
Amanai never explained the omission. He didn't have to. The Uchiha wouldn't share their real power with someone whose loyalty they didn't trust yet.
Muzan spent his days in the tent working through what his body could do. The combat against the Kamizuru had been instinct. Now he approached it deliberately.
His arms could stretch and thin into whips lined with bone protrusions. The extended flesh was pale and distorted but responded to his will without hesitation. He could also compress his forearms into something closer to blades, dense and white, with a cutting edge sharp enough to split the tent's support pole cleanly when he tested it.
He retracted the blade and examined his restored arm. The transformation cost chakra when he initiated it but nothing afterward. The new shape held without maintenance. That was consistent across every change he'd made to his body.
His mind moved to the tree from the ritual. Multiple cores. Consciousness distributed through an entire mass. His own cells behaved similarly. The parallel suggested he might be able to create other beings like himself by introducing his cells into normal humans.
He shelved the thought immediately. He barely understood his own condition. Experimenting with something that could propagate would be reckless.
The hunger continued to build. Every transformation and every act of healing pulled from the same reserve, and rest didn't refill it. Only feeding did. He'd managed to suppress the worst of it so far, but the pressure was constant and getting harder to ignore.
On the fifth night, Amanai arrived with a different expression. His jaw was set and his posture carried weight that hadn't been there before.
"No training tonight," Amanai said. "We're moving to the frontlines."
Muzan looked up at him. "When?"
"Three hours." Amanai stepped inside and crossed his arms. "The Senju broke through our eastern defenses. They're threatening our supply routes. If those routes go down, our forces further north get cut off entirely. We're the reinforcement."
He held Muzan's gaze steadily. "You're assigned to my squad permanently. We handle reconnaissance, sabotage, and assassination. Night operations. Your sunlight problem won't be an immediate issue."
"What am I expected to do?" Muzan asked.
"Follow orders. Stay close to me and Toshiro during engagements." Amanai's voice stayed level. "If you run, I have authorization to execute you. If you perform well, clan leadership might start trusting you. Those are your two options."
He paused and studied Muzan's face. "The Senju aren't bandits. They're among the strongest shinobi alive and they've been fighting this war longer than most people have been breathing. One mistake in front of them and you're dead before you understand what happened."
Muzan said nothing. He understood violence. He'd felt it from both sides already. But saying that would require an explanation he couldn't give.
Amanai seemed to read the silence correctly enough. He nodded once and turned toward the exit. "Three hours. Be ready."
After he left, Muzan sat with the decision for a moment. He could leave now. He knew enough about the geography to navigate. The Land of Iron was north and west, a week on foot at a normal pace, less than half that if he pushed himself.
But leaving felt wrong. The Uchiha had sheltered him during daylight, when he was most vulnerable, and Amanai had taught him skills he would need to survive. Walking away without returning anything felt like a debt he wasn't willing to carry. He would fight with them in this battle. After that, he would leave.
He stood and checked his equipment. Dark clothing for movement. Light armor on his forearms and shins. A weapons pouch on his right thigh. He adjusted the straps until everything sat properly and waited.
The camp transformed over those three hours. Fires died. Voices dropped to short commands and quick confirmations. When Muzan stepped outside, thirty shinobi were already forming into squads and running final checks on their gear. The movement was quiet and organized, everyone operating from the same understood purpose.
Toshiro appeared at his shoulder without sound. "First real battle?"
"Yes," Muzan said.
"Stay behind Amanai-san and me." Toshiro kept his voice low and even. "Don't try to stand out. Just survive and watch."
Amanai arrived in full combat loadout. Chest armor. Extra weapon pouches on both thighs. A sword across his back positioned for a right-hand draw. His face had gone professionally blank. He looked at Muzan once, confirmed he was ready, and turned toward the front of the formation.
Lord Urashi stood on a platform of stacked supply crates. His armor bore the Uchiha crest and his Sharingan was active, the red glow of his eyes visible across the assembled crowd.
"The Senju have broken our eastern line," Urashi said. His voice carried without effort. "If our supply routes fall, our northern forces are finished. We march tonight and we take that ground back."
He let the silence sit for one beat.
"Show them why our clan is feared."
The response came from every throat at once. "Uchiha!"
They moved out immediately.
The squads spread into the forest in tight formation, covering ground fast without breaking discipline. Despite the number of bodies moving through undergrowth, the sound was minimal. Feet found solid ground by instinct and hands cleared branches without noise.
Muzan stayed on Amanai's left and matched his pace. His senses pulled in more than the others could detect: the micro-shifts in air as bodies moved past trees, the faint smell of weapon oil and controlled adrenaline, the exact rhythm of thirty sets of lungs breathing in unison. He kept all of it to himself and focused on moving like the rest of them.
They ran for hours. The forest changed around them gradually, the undergrowth thinning and the trees spacing out until the canopy broke entirely and cleared terrain opened ahead.
The ground had been worked over badly. Scorched patches where fire techniques had burned through everything. Craters from earth manipulation. Trees split at the trunk and lying across each other. The smell of old ash and something sharper underneath it.
Amanai raised his fist and the squad stopped without a sound.
"We're close," he said quietly. He didn't look back at Muzan when he spoke. "Whatever happens next, stay in formation until I tell you otherwise."
Muzan scanned the terrain ahead. Somewhere past that broken ground, the Senju were waiting.
The hunger shifted in his chest, pressing upward like something anticipating release.
He pushed it down and kept his face still.