Inside the underground passage, the air was foul and oppressive, thick with the Fungal Mat's distinctive stench of decay and an intense, chilling energy. Dark purple hyphae writhed like living creatures along the walls and floor, constantly trying to seal the passage Yamato had forcibly opened. Kakashi's Lightning Blade flashed with dazzling blue-white light, cutting through the thick vines surging toward them with the speed and precision of a razor-sharp scalpel. Every strike brought the hiss of scorched hyphae and a brief psychic shriek inside his head.
Naruto followed close behind. Dozens of shadow clones charged forward without fear of death, shielding them with their bodies from attacks coming from the sides and overhead, or grabbing vines and detonating to clear a path for the main force. His real body kept forming Rasengans and blasting the especially tough core vines that even the Lightning Blade could not sever in an instant.
"It's just ahead, Kakashi-sensei!" Naruto shouted. He could clearly feel the deeply unsettling energy ahead growing stronger. "That nasty feeling is getting worse!"
Kakashi's Sharingan also picked out the source at the end of the passage: something pulsing like a heart and radiating an intense dark purple glow. It was a massive "mycelial core," roughly as tall as a person, formed from countless intertwined hyphae and distorted energy. Rooted deep underground, it had countless energy channels connecting it like blood vessels to the cage above and the entire Mycelial Carpet Forest. Its surface rose and fell as though it were breathing, giving off mind-scrambling whispers and powerful corrosive energy.
"That's the core! Destroy it!" Kakashi barked, accelerating again as the light of his Lightning Blade grew more concentrated.
But just as they were about to reach the mycelial core, everything changed!
The Mycelial Core suddenly pulsed violently, unleashing a