The target was a Hyuga branch family member. Low-level jonin. Stationed alone at a border outpost in the Land of Rivers.
Perfect.
"His name is Hyuga Riku," Kabuto explained, showing Sasuke the intelligence file. "Branch family. Caged Bird Seal active. He's been assigned to a listening post—basically exile for minor infractions."
"Why is he alone?"
"Hyuga clan doesn't waste resources on failures. He's on monitoring duty only. No backup for fifty kilometers." Kabuto smiled slightly. "No one will notice if he disappears immediately."
Sasuke studied the file. "The Caged Bird Seal. Will it interfere with absorption?"
"Unknown. The seal destroys the Byakugan on death. But if you absorb it while he's alive..." Kabuto pulled out a scroll on Byakugan anatomy. "The seal might not trigger. It's designed to prevent the eyes from being taken after death, not during life."
"Only one way to find out." Sasuke closed the file. "I leave tonight."
Two days later, Sasuke stood outside Riku's outpost.
Small building. One occupant. Minimal defenses. The Hyuga was inside, probably bored.
Sasuke didn't knock. He simply walked through the door.
Riku spun from his desk. His Byakugan activated instantly, veins bulging around his eyes.
"Uchiha," Riku said, shifting into a defensive stance. "What are you doing here?"
"I need your eyes."
Riku's expression hardened. "You'll have to—"
Sasuke moved. Lightning fast. His Sharingan predicted Riku's Gentle Fist counter before he made it. Chidori formed, struck low—not to kill, but to cripple.
Riku collapsed, his leg's chakra network disrupted. He tried to rise, but Sasuke was already on him.
"Don't fight," Sasuke said calmly. "It's already over."
He pressed his hand to Riku's face. Mangekyo activated. Takama-ga-hara blazed.
The connection formed immediately. But different from Sharingan absorption. The Byakugan's structure was alien. Foreign. His Mangekyo struggled to interpret it.
Riku screamed. His Byakugan flared with chakra. The Caged Bird Seal began to glow—
Sasuke pushed harder. His Takama-ga-hara adjusted, learning the Byakugan's structure on the fly. The 360-degree vision network. The chakra point perception. The near-perfect sight.
Different from Sharingan. But his Mangekyo was adapting.
Pull.
The Byakugan's chakra structure began transferring. Slowly. Carefully. Sasuke's eyes burned with the integration process.
The Caged Bird Seal flared brighter—then stopped. Confused. The Byakugan wasn't being destroyed or removed physically. It was being... transferred. Absorbed. The seal's parameters didn't cover this scenario.
Twenty seconds. Longer than Sharingan absorption. But it worked.
Riku's Byakugan faded. His eyes returned to normal. The veins around them vanished.
Sasuke released him. Riku collapsed, gasping. Alive. His dojutsu gone.
"Please..." Riku whispered. "I won't tell anyone—"
Sasuke's hand moved. Lightning blade formed. Precise strike through the heart.
Riku died instantly.
No hesitation. No remorse.
Sasuke stood, forming hand seals. "Fire Style: Fireball Jutsu."
The massive fireball engulfed the building. Flames consumed everything—Riku's body, the outpost, all evidence. Within minutes, only ash and burning wood remained.
Sasuke turned and left. His eyes throbbed violently. The Byakugan's structure was fighting with his Uchiha genetics. Not full rejection, but significant incompatibility.
By the time he was a kilometer away, pain had spread through his entire skull. Blood leaked from his eyes.
But it was done. The test was successful.
Cross-family dojutsu absorption was possible.
Now he just had to survive the integration.