He learned the limit by breaking it.
The tunnel narrowed until stone pressed close on both sides, heat breathing through hairline cracks like a sick animal. He had chosen it because smaller spaces restricted numbers. Restricted numbers reduced variables.
That logic held.
Everything else failed.
The first demon came at him low and fast, a lean carrion-eater with blade-jointed limbs and a ribcage that flexed as it ran. He stepped in, let the claws rake his shoulder, and answered the way he always did—
Cold surged.
Too much.
Ice exploded outward from the wound instead of sealing it. His arm locked mid-motion, muscle frozen solid. Pain bit hard enough to blur the edges of his sight.
The demon didn't stop.
It slammed into him, momentum carrying both of them into the wall. Stone cracked. His frozen arm shattered from elbow to wrist, ice and bone fragments spraying in a white-red fan.
The limb came away useless.
The demon shrieked in triumph and tried to tear into his throat.
He used the broken arm anyway.
He drove the splintered ice stump into its mouth and pushed. Ice fractured teeth, forced jaws open wider than anatomy allowed, then expanded violently. The skull split along the seams. Gray matter spilled, froze, and dropped in brittle chunks.
The body collapsed.
He staggered back, breathing ragged vapor, staring at what remained of his arm.
Blood did not flow. It crystallized, sealing the stump in jagged layers of frost that burned almost worse than heat. Sensation vanished in pulses, returning only as distant pressure.
Too much cold, he noted, detached. Wrong direction.
Footsteps scraped behind him.
Two more demons entered the tunnel—thicker bodies, slower, armored with layered hide that radiated heat in rolling waves. They smelled blood. They smelled weakness.
He planted his feet and tried again, forcing control.
Ice crawled along the ground this time, sluggish, uneven. He shaped it instinctively into crude spikes between himself and the demons.
They shattered immediately.
The armored demons charged through, their weight crushing the frozen growths into glittering debris. One slammed a horned head into his chest.
Ribs caved. Lungs spasmed.
Heat flooded him, uncontrolled, and his core panicked in response. Cold erupted inward.
His left lung froze.
Breath cut off mid-inhale. Pain went sharp and blinding as ice spread across tissue that was still trying to function. He dropped to one knee, vision tunneling, frost leaking from his mouth in a violent cough.
The demons closed in.
He did not retreat.
Retreat required air.
He reached out with his remaining hand and grabbed the nearest demon by the thigh. The heat there was dense, muscle packed and working hard.
He pulled.
Not strength. Direction.
Cold focused into his grip and he held it there, denying the heat escape.
The demon roared as its leg seized, joints locking. Ice crawled up muscle fibers, thickening, anchoring.
The second demon struck him from behind, claws tearing into his back, ripping skin and muscle open to the bone. Pain flared white-hot, then vanished as frost snapped shut around the wounds, sealing them crude and thick.
He turned with the motion, dragging the frozen legged demon into the other.
They collided hard.
He drove his weight forward and shoved, using the frozen limb as leverage until it tore free at the hip in a wet, cracking sound. The demon collapsed screaming, clutching a stump that smoked briefly before frosting over.
The other demon hesitated.
That was enough.
He lunged, bit into its throat, and released everything he had left.
Cold flooded unchecked.
The demon froze from the inside out, organs locking before flesh could compensate. Its chest split with a muffled crack as expanding ice ruptured bone. It died without another sound.
He fell with it.
The tunnel went quiet except for the hiss of cooling stone.
He lay on his side, vision flickering, chest heaving shallowly through one functioning lung. His shattered arm lay a short distance away, already rimed white, blood crystallized along snapped edges of bone.
He assessed without emotion.
One arm lost. One lung frozen. Multiple fractures. Severe strain.
Not fatal.
Not yet.
He crawled.
It took time—unmeasured, uncomfortable time—to reach the crevice he'd used before. He dragged the bodies in after him, teeth chattering not from cold but from the effort of holding it back.
He fed poorly.
Rushed bites. Half-frozen flesh. Heat intake uneven.
His core tightened painfully, rotation stuttering as it tried to compensate for conflicting signals. Ice spread where it shouldn't, creeping into muscle groups already damaged, stiffening movement further.
He stopped eating.
More would destabilize him.
That realization was new.
He pressed his back against the stone and waited, forcing the cold to compress inward, ignoring the way it fought him. His chest ached as the frozen lung cracked internally, ice fracturing under residual heat.
He allowed it.
Fracture created pathways.
Hours passed. Or something like hours.
Eventually, sensation returned as pins and pressure. The frozen lung thawed unevenly, tissue sloughing and reknitting wrong. He coughed up a thick plug of frozen blood and breathed shallowly again.
The stump at his shoulder shifted.
Regeneration began.
Flesh crept outward in slow, ugly increments, guided by heat drawn from the bodies beside him. The new arm formed thicker at the shoulder, bone denser, growth uneven where ice had reinforced some structures and not others.
He watched it happen with clinical focus.
When the arm finished forming, it was heavier than before. Movement felt different—more resistance, more leverage.
Not better.
Different.
He flexed it once and winced as pain flared down the length of it.
Structural reinforcement occurred before control, he concluded. Sequence inverted.
That mattered.
He tested the cold again, carefully this time, letting it bleed into his fingertips in a thin stream. Ice formed slowly, obeying direction for a fraction longer before cracking away.
Improvement measured in heartbeats.
He leaned his head back and closed his eyes, not resting—just reducing input.
The fight replayed in fragments: the arm freezing instead of sealing, the lung locking, the spikes shattering under weight.
Patterns emerged.
Cold followed blood fastest.
Large shapes failed under heat pressure.
Internal freezing required timing, not volume.
He reached one slow, dangerous conclusion:
He was not strong enough to use ice yet.
Only to survive it.
That night—if time could be called that—something tried to enter his crevice. A cautious thing. Smaller. Curious.
He snapped awake instantly and reacted on instinct, flaring cold outward in a reflexive burst.
The ice exploded.
Stone cracked. Frost leapt uncontrolled, sealing the entrance entirely.
He screamed as the backlash tore through him, internal ice ripping along old damage lines. His new arm fractured again at the forearm, bone snapping clean.
Silence followed.
He lay panting in the frozen dark, body shaking, surrounded by the groan of cooling stone.
Unacceptable, he decided.
Not the pain.
The waste.
He spent the next long cycle doing nothing but undoing damage—thawing too-frozen tissue manually, forcing heat back into places that locked, feeding in precise amounts instead of gorging.
It was slow.
It hurt constantly.
And when he finally stood again, whole but altered, he understood something fundamental without ever naming it:
Growth here was not about gaining.
It was about not losing control.
He stepped out of the sealed crevice and looked at the tunnel he had nearly died in.
The ice scars remained. Cracked stone. Frozen blood fused into the walls.
Evidence.
He touched the wall and let a controlled thread of cold pass from his palm into the stone.
It held.
Just for a moment longer than before.
Enough to matter.
He withdrew it and turned away, moving deeper, careful with every step.
This body was unstable.
That was acceptable.
Instability could be measured.
And measured things could be corrected.
Eventually.