Facing the unpredictable frost dragon, Kael immediately apparated to evade its attack.
He reappeared atop the beast's massive head, wand raised high, "Avada Kedavra!"
A brilliant green light struck the dragon's skull, causing it to stiffen and roar in agony that echoed across the frozen landscape.
Kael cursed under his breath and vanished again before the dragon could retaliate.
As an ancient dragon created by Morgoth himself in the First Age, the frost dragon Glam possessed a soul of immense power. Even the Killing Curse could only gravely wound rather than destroy it outright—a testament to its primordial strength.
The severely injured Glam descended into utter madness, roaring with rage that shook the very earth, "Wizard, I will tear you apart!"
It attacked Kael relentlessly, spewing waves of chilling breath that turned the air itself to glittering ice crystals. Its enormous body caused the ground to tremble with each thundering step, leaving deep craters in its wake.
Kael used constant apparition to evade the onslaught, subtly drawing the frost dragon away from Isengard and toward the open plains beyond.
Smaug arrived to assist, golden scales gleaming as he dove from above.
Though vastly different in size, Smaug's ability to fly shortened the power gap considerably. He employed agile aerial combat, continuously breathing scorching fire that sizzled against the frost dragon's icy armor.
Thorondor, with his powerful wings and keen eyes, harassed the enemy from unexpected angles, swooping down to claw at damaged scales and tear away chunks of frozen flesh.
The frost dragon howled in pain, angrily lunging at Thorondor with snapping jaws. The eagle dodged with practiced ease.
The dragon then felt sharp pain on its tail. Looking back, it spotted Cerberus biting down fiercely with all three heads, shaking violently to tear through scale and sinew.
Cerberus's toxic and corrosive teeth had pierced through the dragon's supposedly impenetrable scales, causing genuine pain for the first time in centuries.
At ten meters tall, Cerberus appeared as a mere insect to the colossal frost dragon. Annoyed beyond reason, it whipped its massive tail with tremendous force, hurling Cerberus through the air like a ragdoll.
The three-headed dog crashed against a distant mountain with a sickening thud, sliding down the rocky face and collapsing in a heap of fur and blood.
Cerberus whimpered once, then lay still, unable to continue fighting.
Kael glanced with deep concern at his fallen companion, then turned back to the frost dragon with eyes cold as winter steel.
With this emotional shift, Kael's eyes turned pure white. Black mist began rising from his body like smoke from dying embers. His physical form dissolved into formless, swirling dark mist—the Obscurus unleashed.
The mist surged toward the frost dragon at impossible speeds, faster than wind or thought, ravaging the ancient beast with pure destructive power.
The darkness moved like countless grains of black sand, grinding away at the dragon's hardened scales with relentless force. It exposed vulnerable skin beneath, then invisible forces tore at the flesh, causing rivulets of ice-cold dragon blood to flow and steam in the air.
Yet even this was not enough. The frost dragon was truly formidable. Kael's Obscurus form could only wound the exterior, unable to deliver the fatal damage needed to end this battle.
The dragon sprayed freezing breath over its own body, forming thick ice like plate armor that covered every vulnerable spot.
Both Smaug's fiery breath and Kael's shadowy attacks could only damage the outer ice layer, unable to penetrate and harm the dragon's true body beneath.
The frost dragon had become even harder to defeat.
It soon detected Kael's strategy to lure it away from Isengard and the warriors sheltering there.
Its ancient eyes scanned the Dunlendings, Rohirrim, and others gathered beneath Orthanc's shadow. A cruel sneer crossed its draconic features.
"You care about these mortals? Then I shall freeze this entire place into a tomb of ice!"
Without allowing Kael time to respond, it breathed chilling frost in a wide arc. Temperatures plummeted instantly. Frost coated the ground in spreading patterns. Breath turned to visible vapor, then to tiny ice crystals that hung suspended in the frigid air.
Everyone felt bone-deep cold seeping into their very marrow—if left unchecked, all would freeze solid within minutes.
Kael solidified his upper body from the Obscurus form, flying swiftly to Isengard's walls. He raised his wand and summoned blazing Fiendfyre with desperate intensity.
The cursed fire spread rapidly, forming a towering wall of flames around Isengard's perimeter.
The fiery barrier blocked the spreading cold, creating a sharp boundary between winter and inferno.
Kael transformed fully into a Fiendfyre demon wreathed in living flame. He cracked a whip of pure fire against the frost dragon's icy armor with explosive force.
Though the fire caught and spread across the dragon's body, the beast countered by breathing ice that extinguished the fiery whip in a cloud of steam.
Fire and ice clashed in elemental fury, neither able to completely overcome the other. Each relied on overwhelming quantity to suppress their opponent.
Thick icy mist settled over Isengard, reducing visibility to almost nothing.
Then the frost dragon's chilling breath transformed the mist into countless floating ice crystals that caught the light like deadly diamonds.
Amid the obscured battlefield, Herpo silently slithered behind the frost dragon with serpentine grace. He struck at unscaled areas near the joints, injecting every drop of his potent venom.
The frost dragon reared back in sudden pain, turning to breathe an icy blast at the serpent.
But it made the fatal mistake of meeting Herpo's glowing orange eyes directly.
Struck by the basilisk's deadly gaze for a second time, its ancient soul suffered further catastrophic damage. The dragon roared in pure agony, thrashing wildly.
Kael materialized beside the dragon's massive head, wand aimed with deadly precision, "Avada Kedavra!"
Suffering the basilisk's venomous stare and Killing Curse in rapid succession, Glam's soul fire flickered and dimmed dangerously.
Surrounded by Kael, Smaug, Thorondor, the basilisk, the Fiendfyre demon, and the cautiously advancing Dunlendings and Rohirrim with their enchanted arrows, the frost dragon felt genuine mortal threat for the first time in an age. Ancient fear crept into its heart.
As one of the last surviving dragons from the Elder Days, it valued its long life above all else. It spewed cold in all directions to repel its attackers, then turned and fled with surprising speed toward the looming Misty Mountains.
Knowing that Rohan lay to the east, Gondor to the south, and Enedwaith to the west—all populated lands where pursuit would be relentless—it fled north into the rugged, maze-like Misty Mountains where it might hide and heal.
Unable to fly with its torn wing, it relied on its massive stature and powerful limbs to move with desperate speed across the broken terrain.
"Chase it! Don't let it escape!" Kael shouted, transforming into pure Obscurus form. He pursued the fleeing dragon like black wind made solid.
This was not mercy but cold calculation—Kael sensed the dragon's vengeful spirit and cunning mind. It would be a dangerous enemy if allowed to survive and plot revenge.
Kael's Obscurus form was weightless and formless magic energy, allowing him to fly fast enough to catch the retreating beast.
The frost dragon suddenly pivoted with surprising agility, breathing concentrated cold directly at Kael's approaching darkness.
Obscurus Kael split into swirling mist, dodging the deadly breath. He reformed instantly and engulfed the dragon like a suffocating black veil, eroding its icy armor with grinding force.
The frost dragon howled in renewed pain, spraying more freezing breath over itself. It added layers of protective ice, attempting to freeze the Obscurus and trap it within solid crystal.
Even in Obscurus form, Kael dared not face that supernatural cold directly. He retreated with tactical precision, reforming at a safer distance.
Smaug and Thorondor continued their relentless pursuit through the air. Herpo clung to Smaug's back, ready to strike again.
Smaug breathed scorching fire at the frost dragon's retreating form, while Herpo prepared to use his killing gaze once more.
The frost dragon's ice breath barely fended off the flames. When the cold faltered for just a moment, it fell victim to the basilisk's eyes yet again. The blow to its soul was devastating. Its breath of cold halted entirely, allowing Smaug's fire to finally melt through its icy armor.
Thorondor seized the opportunity, diving with talons extended. He clawed through shattered scales, tearing away great chunks of exposed flesh.
The frost dragon cried out in agony that echoed through the mountains.
Kael struck once more with the Killing Curse, the green light finding its mark.
The frost dragon's soul fire dimmed to a mere flicker, as if death itself approached on silent wings.
Feeling its life rapidly fading away like water through grasping claws, the ancient dragon roared with fierce hatred and desperate resolve.
"You want me dead? Then we shall all die together!"
It erupted with unbearable cold from deep within its core, bellowing a low-frequency draconic incantation that invoked the raw power of nature itself.
"Watch out, Master! It's sacrificing its life force with dragon magic! Retreat now!" Smaug warned with urgent desperation.
Kael instantly retreated in Obscurus form, pulling back at maximum speed.
A massive wave of ultimate cold exploded outward from the frost dragon like a detonation of winter itself, freezing everything in its expanding radius.
Trees, stones, and unfortunate birds still in flight—all froze solid in an instant, perfectly preserved in crystalline ice. Even the air itself shimmered and crackled, glistening with frozen particles.
This was the frost dragon's ultimate power, purchased with its own dwindling life force.
The deadly cold covered over ten miles in all directions.
Thanks to Smaug's timely warning and Kael's swift retreat and protective shielding, they avoided the coldest core and emerged unharmed.
Thorondor, Smaug, and Herpo retreated just in time, though they were covered with thick frost that clung to feathers and scales.
Herpo grew lethargic from the cold, teetering on the edge of serpentine hibernation.
The frost dragon, standing at the frozen epicenter of its own devastating magic, had not perished. But it had sacrificed a significant portion of its remaining life force.
Now critically weakened, it could barely summon enough strength to breathe even with the weakest cold.
It turned without looking back, limping deeper into the Misty Mountains with the last of its fading strength, disappearing into shadow and stone.