Yuki-onna's Ice Release formed a thousand ice spikes in midair, which shot furiously toward Muon.
But the modified Muon didn't care about attacks of this magnitude. His sixteen tentacles whipped wildly, shattering every ice spike.
"Do you still not understand?" Muon laughed maniacally. "I'm invincible in this fortress!"
Sasuke's Rinnegan finally spotted the key. At the very center of Muon's body was a fist-sized metal core, with every pipe connected to it.
"Found it! The core's in his chest!"
Naruto understood at once. The Nine-Tails Chakra surged forth at full force. "Then let's smash it!"
He formed the biggest Rasengan he could, combining it with the Natural Energy of Sage Mode. The entire technique shone with a dazzling light.
"Super Great Ball Rasengan!"
But just as Naruto was about to hit his target, Muon's expression suddenly turned strange.
"You think I'm going to let you get away with that?"
He abruptly pressed the core in his chest.
"If I'm going to die, then we'll all die together! Self-Destruct Program, activate!"
A shrill alarm rang throughout the fortress. All the energy pipes began to overload, the Culture Tanks exploded one after another, and countless cracks spread across the walls and floor.
"Damn it! He's going to blow up all of Hozuki Castle!" Sasuke's expression changed.
Karin's sensory abilities spread out in full, and her face instantly turned deathly pale. "The main force outside has already begun its attack! If this place explodes, at least five hundred people will be caught in it!"
Naruto gritted his teeth and tried to stop him, but Muon had gone completely insane. His body began to break apart, metal and flesh fusing together into a massive ball of energy.
"Ten seconds! You have only ten seconds to escape!" Muon's voice warped. "But you won't get away!