Arctos Gorehowl is more than a Chaos Lord, but not quite a Daemon Prince. His soul and essence are tied to those of his warp dragon mount (who is as of yet unnamed), who is itself a greater daemon of sorts. As a result, he has achieved immortality in his own way. No less a slave to the Bloodfather than a prince or proper daemon, but he retains his mortal frame.
Here is the story of his triumph:
With a grunt, Arctos Gorehowl yanked the blade of Heartseeker from within the smoking mouth of the fallen bloodthirster. The daemon-spear was unblemished by the beast’s flaming breath, nearly vibrating with delight at bathing in the blood and brain matter of its greater cousin, whose corpse twitched on the blood-soaked sand of the arena.
Arctos’ equerry Viconius strode from the crowd of spectators to his master’s side. Ornate brass power armor obscured the once beautiful Astartes within. A son of Sanguinius in a former life, now another slave to the blood god.
Gorehowl silently passed Heartseeker to his equerry, and reached for the hilt of the rune-encrusted scimitar at his waist. Pulled free of its sheath, the curved blade began to growl like a dog fighting over a bone. With his free hand, the warlord raised the slain bloodthirster’s head by the icon of Khorne crowing its cranium. It took three vicious strokes of the growling blade to hack through the spine and neck muscles before loosing a bark of delight when it finally severed the massive head.
Roaring in triumph, Gorehowl lifted the mangled head before the gathered throngs of Khorne, blood pouring over his scorched armor. The warriors of the Brass Stampede erupted in a roar of their own at their master’s victory, joined by the daemons of the fallen bloodthirster’s legion. A new lord had risen to lead their hosts, proven mightier than the last in the sand of a million pulverized skulls.
“Bloodfather! Your son offers a skull!”
Forked bolts of crimson lightning split the sky above the arena, thunder booming Khorne’s approval of one champion slaughtering another. The dark clouds began glowing, lightning spitting and crackling from within the voluminous gloom.
The sound of thunder was almost like laughter; a god’s amusement at the squabbles of playthings desperate for his approval. And yet, he was pleased.
A shape broke through the darkness of the clouds like a meteor, red electricity arcing in its wake. Folded wings and a long tail became visible as the shape plummeted toward the arena.
Viconius chuckled. “Another thirster to slay, is it?”
“No,” Arctos uttered while slowly lowering his victim’s severed head. “Something else. Something we’ve never seen before.” He quickly sheathed his scimitar and extended his hand toward his equerry, his gaze never leaving the descending monster. His gauntleted fingers closed around the shaft of Heartseeker.
The creature’s great wings unfurled a split second before it slammed into the ground, spraying bonesand across the arena. Four mighty limbs supported the daemon’s massive body, each ending in wicked talons. A thick, serpentine neck held its head aloft: horned, crested; with eyes that conveyed the unbridled malice of its spirit. Screeching, it stomped toward the warlord and his equerry.
Gorehowl smiled beneath his helm. “A warp dragon.”
Viconius stepped away, having no right to engage the beast alongside his master. The glory of a skull champion’s challenge is not willingly shared with his underlings. A part of him was eager for his master’s death. If the equerry had the chance to slay the dragon in Arctos Gorehowl’s blood, command of the new legion would pass to him. But first, the warlord would have to fall.
Arctos thrust his spear skyward, unfazed by the dragon’s approach. As he did, a bolt of crimson lightning struck the spear, its energy coruscating down the blade, through the shaft, and over the surface of the warlord's fire-blackened suit of power armor. A change came over Gorehowl – an understanding. Muffled laughter was audible even through the battered brass faceplate of his horned helm.
The dragon folded its wings and halted its advance a dozen paces from the lord of the Brass Stampede. Arctos took a spinning step forward, gathering momentum to toss the bloodthirster’s severed head at the dragon.
Thick jaws snapped shut around the head, crunching into the skull and mangling its brass icon. The great daemon lifted its head and neck to swallow the prize, now a lump in its throat descending toward the furnace of hellfire within. Sated, it lowered its head to lock eyes with Gorehowl.
Arctos dragged Heartseeker’s blade across the palm of his gauntlet, effortlessly slicing through the ceramite and into his flesh beneath. He clenched his fist and raised it to the side, a steady rivulet of blood streaming forth which the dragon greedily gulped down.
The warp dragon bowed its body, revealing a saddle between the shoulders of its wings. Arctos Gorehowl mounted the beast, and again the legions of Khorne gloriously roared to the triumph of their lord.
Now the equerry understood. He turned to the slaughter-brothers standing beside him. “Behold his ascension.”
Though not physically reformed as daemonic royalty, Arctos Gorehowl was forever soul-bonded to the dragon, inseparable and everliving. The galaxy was already fearful of the carnage wrought by of the Brass Stampede, but a new terror cast a winged shadow to herald the bloodshed to come.