Trollhunters: welcome to the darklands

Prologue: hexile

"Gunmar the Black howled.
He howled in confusion, unable to tell day from night in this strange new realm. He howled in pain. Ice-cold winds whipped against his body—a body born in the fires of war. And he howled in defeat. Victory had been snatched from his grasp, just as Gunmar had been snatched into these dark lands.
Gunmar forced himself to stand. His hooves nearly slipped on the glowing green rock beneath him, but he found his balance.
Never again will I be brought to my knees, Gunmar promised himself.
He looked out at the Darklands with his single burning eye and watched his army start to appear around him. One by one, thousands of Gumm-Gumm soldiers arrived in flashes of blinding white light. They, too, crashed against the barren landscape, as Gunmar had done mere seconds ago. They, too, fell over

"with vertigo and shivered against the sudden cold.
Gunmar turned his horned head upward and saw the portal through which he and his army had been thrown. Killahead Bridge sat atop a jagged stone peak. Its arch shimmered with magic as more Gumm-Gumms plummeted into the Darklands.
Gunmar squinted his eye and stared through the portal. He glimpsed the distant surface world on the other side, as well as the enemy who had just banished him from there.
"Deya," said Gunmar with a low growl.
Deya the Deliverer stood guard at the other end of Killahead Bridge. Her silver Daylight Armor was battered and dirty from weeks of combat, but still unbroken. She planted her broadsword into the battlefield, a grim look of finality in the Trollhunter's eyes. Even across the immeasurable space that separated them, Deya's message was clear: this war is over.
"No!" Gunmar shouted.
He sprang into the air and climbed the peak toward the bridge like a wild animal. Gunmar's claws tore into the rock. He pulled himself higher, dodging the Gumm-Gumms that

"still fell out of the portal and past him. His body heaved, and his glowing blue veins pumped with energy. But Gunmar did not stop. He closed in, never taking his eye from Deya.
With only a few feet left between Gunmar and the Trollhunter, Deya reached up to her side of Killahead.
"No!" Gunmar yelled again, fangs gnashing in anger.
Deya's fingers closed around the Amulet embedded in the top of the bridge. Gunmar leaped toward her. His massive legs propelled him across the remaining distance.
"NO!" Gunmar shouted one last time.
But he was too late. Deya removed her Amulet from the bridge a second before Gunmar reached her. And the portal to the surface lands closed.
Gunmar's body hurtled through the now-empty air and collided with Killahead Bridge, reducing it to rubble. The inert fragments of the bridge then began to vanish around him, just as the portal had disappeared before his very eye."

"Wrenching open his jaws as far as they could go, Gunmar the Black unleashed his most awful howl yet. The primal scream echoed across the Darklands for quite some time. When his wail finally faded, Gunmar looked down the peak to his army. The Gumm-Gumms all stared back at their fallen king, each too frightened to even blink under their heavy metal helmets.
"My son," Gunmar whispered, his throat raw. "Where is my son? Where is Bular?"
Unsure of how to respond, the soldiers looked at one another. Some shifted nervously, their weapons and armor clanking in the awkward silence.
"My lord," called a voice from below Gunmar.
The crowd of Gumm-Gumms parted, and a muscular, orange-skinned Changeling stepped forward. He swept his cape to the side and gave a slight bow in Gunmar's direction.
"Speak, Kodanth," said Gunmar to the Changeling. "For the information your Impure spies bring has always proven valuable."
"The last I saw of mighty Bular, he was slashing most valiantly through the Troll"

"hunter's forces, along the southern front," said Kodanth. "Might I suggest you question your general stationed in that vicinity?"
Gunmar fixed his glare upon a particularly large Gumm-Gumm whose body was decorated with stripes of war paint, and said, "The south was your assigned area."
"Y-yes, my lord," stammered the striped general.
"Then what news of my son?" demanded Gunmar.
"F-forgive me," answered the general after a long pause. "But Bular, he . . . deserted us!"
"What did you say?" Gunmar asked quietly, his eye narrowing into a flickering slit.
"That Krubera turncoat, AAARRRGGHH!!!—he switched sides and began fighting with the Trollhunter, not against her," explained the Gumm-Gumm. "Bular met AAARRRGGHH!!! on the field of battle, and they fought fiercely. But the traitor struck a lucky blow. He broke off part of the horn from Bular's crown."
The general pointed to his own right horn to indicate what had happened and then said, "Bular clutched his wound and fled before the"