The mountain night was cold. Mist crawled over Kukuroo's slopes like pale fingers, wrapping the estate in silence. But deep within, beneath stone and steel, there was no silence—only the sound of fists striking flesh, blades cutting air, and the quiet commands of assassins shaping children into killers.
Kaien stood in the center of the northern training hall, chest bare, long dark hair tied back to keep it from his eyes. Sweat rolled down the ridges of his muscles. His aura shimmered faintly against the lantern light, Ten wrapped tight around his frame like a thin second skin.
"Hold it," Zeno's voice cut sharp.
Kaien's shoulders ached, his legs trembled, but he focused. He pictured the aura not as water spilling everywhere, but as a cloak clinging close. He pulled it tighter, breath slow.
From the side, Illumi sat watching, knees drawn up to his chest, hair hanging loose around his face. His eyes never blinked, never moved. Just stared.
Kaien hated that stare—it was neither admiration nor scorn. It was a mirror that reflected nothing back.
The old man's aura surged suddenly, crashing down like a storm. Zeno's presence filled the hall, crushing, suffocating, pressing against Kaien's lungs.
"Don't leak."
Kaien's knees buckled. His aura shivered, fraying at the edges. His heartbeat roared in his ears.
Hold. Hold. Don't let it slip.
He gritted his teeth, forced his energy to cling. The trembling slowed. The veil of Ten, thin but unbroken, held steady.
Finally Zeno withdrew, chuckling. "Better. Still sloppy, but better."
Kaien collapsed onto one knee, chest heaving, sweat dripping from his chin. He glanced up to see Silva watching from the shadows above, arms crossed, expression unreadable.
"Strength is nothing without control," Silva said, his deep voice rumbling like distant thunder. "And control is nothing without strength. You'll have both, or you'll die young."
The next trial came at dawn.
The butlers led Kaien to the Beast Yard, where the Zoldycks kept caged monsters for training. The air reeked of fur and iron. Chains rattled as a massive wolf-beast snarled from its pen, eyes glowing faintly in the dim light.
Silva's hand rested on the cage. "Kill it."
Kaien's throat tightened. The creature was no man. It was a predator, built for the kill, muscles bulging under thick hide, jaws strong enough to crush bone.
But hesitation was weakness. He stepped forward, blades drawn. His aura flickered, clinging to the steel, shimmering faintly.
The cage opened. The beast lunged.
Kaien rolled aside, aura wrapping his arms as claws raked past. He slashed upward, blade biting deep into fur and flesh. Blood sprayed. The beast howled, but didn't falter.
It came again, faster. Kaien braced, aura flaring harder than ever before—Ren, though he did not yet know the name. Power burst from him, his whole frame vibrating with strength. His blade cleaved down, striking the beast's skull. The impact shook the yard.
Silence.
The creature collapsed, twitching once, then stilled.
Kaien panted, blood dripping from his blade. His aura still roared around him, wild, uncontrolled.
Zeno clapped slowly. "Ah. There it is. Ren, in its roughest form. Raw, violent, wasteful. But it woke."
Kaien blinked, chest heaving. Ren?
Silva's cold eyes fixed on him. "Control it. Or it will eat you alive."
That evening, Kaien sat cross-legged in meditation, skin still stained with blood. His body ached, but his mind replayed the fight. The moment he had flared. The moment something inside him screamed and burst outward.
It had felt… intoxicating.
And terrifying.
Zeno's voice came from the shadows. The old man always appeared without sound, his steps softer than mist. "Do you understand it yet?"
Kaien kept his eyes shut. "Power. But wild."
Zeno chuckled. "Ren is life force, forced outward. It strengthens body, heightens presence, magnifies killing. But without control, it bleeds you dry. You'll learn to ignite it without burning yourself."
Kaien breathed deep, focusing. He tried to summon the flare again, to feel that raw rush. His aura pulsed outward, stronger than Ten, but shaky, unstable.
Zeno smacked the back of his head. "Too much! You're spilling everywhere. Ren isn't a tantrum. It's a knife's edge."
Kaien winced, forcing it inward, narrowing the flood until it hummed faintly around him. Still unstable. Still rough.
Illumi's voice drifted from behind. "You'll waste yourself if you keep straining like that."
Kaien opened his eyes. Illumi stood in the doorway again, pale face unreadable.
"You never sleep, do you?" Kaien muttered.
Illumi didn't answer. He only tilted his head. "The first time I used Ren, I blacked out for three days. Don't let that happen."
And then he was gone.
Kaien exhaled slowly. So even Illumi struggled. Good. That means I can surpass him.
Days bled into weeks. Training became torment.
Kaien sparred Illumi again and again, each time with Nen as the focus. His cousin was always calm, always precise, aura never wasted. Kaien, taller and stronger, pushed with sheer force, but Illumi's control sliced his every effort apart.
Silva unleashed him into trap corridors lined with hidden blades and weighted doors, ordering him to maintain Ten throughout or be cut down. Kaien stumbled home bloodied night after night, but alive.
Zeno pressed him into meditation until his legs went numb, aura whispering, slipping, stabilizing.
Kikyo only smiled when she passed him in the halls, her words like knives: "My sons were never so clumsy at your age. Perhaps you'll live long enough to catch up."
Kaien swallowed the bitterness. He said nothing.
But inside, he swore he would not only catch up. He would eclipse them all.
One night, Zeno forced him into the pit again.
This time, not Illumi.
Three butlers stepped forward, each trained killers in their own right.
"Hold Ten. Use Ren. Do not break Zetsu when ordered," Zeno barked.
The fight was chaos. Aura flared against aura. Blades flashed. Kaien staggered under the pressure of three at once, but he pushed his aura outward, strengthening limbs, parrying, countering. His Ren burned hot, his Ten clung tight.
When Zeno suddenly barked "Zetsu!" Kaien slammed his aura closed, vanishing completely. The butlers blinked, momentarily blinded by his absence. Kaien lunged, blade at one's throat.
The match ended there.
Zeno's smirk widened. "Better. The boy learns."
Silva only gave a curt nod. "He'll be ready soon."
Kaien sheathed his blades, chest burning, sweat stinging his eyes. His body screamed, but his mind whispered only one thought:
Ready for what?
He already knew the answer.
Another mission. Another kill. Another step deeper into the abyss.
But for now, he was still in the forge.
And the fire was only growing hotter