As the Kunst Meister tried to move with caution, the twist brought him a chorus of pangs along the neck, till exploding within his head its white vowel of pain. Far away, to the south, the white smoke of the stalled hoverbike no longer stood out from the purple sky. Everything in that cursed place was wrong and the black powder was a whisk, shaken by the suffocating wind of a perverse and tireless djinn. Now he had the certainty that all those stories whispered by candlelight were not only true, but also a pale and dull representation of the deafening truth in front of his eyes. At every shallow breath, the macabre dunes of the Obsidian Desert reminded him of the long distance covered. Since he had left the hoverbike behind him, he had tried to taunt himself about the creeping and imperceptible movements of the sand. By now, however, it was no longer possible to ignore it: the dunes had definitively assumed the shape of deformed faces. The Meister struggled not to look at them but could not ignore those soulless empty orbits, which peered his every uncertain step. Those mounds were reproducing his face, multiplied in a kaleidoscope of abomination. Among the dunes, madness used to arrive well before dehydration. He almost did not notice that the Tesseract 19 could be seen to the naked eye, right at the horizon. The column pierced the black sea and challenged the streaked clouds. The awareness of his distance made him wince. That construction was huge, that artifact was Moloch's sharpest tooth. The warm wind delivered to him, intertwined with dust, an imperceptible howl: the wail of the monolith, an omen of death. The man waited, an immobile exoskeleton bent over the black sand. The helmet laying abandoned beside him. Soon everything would be accomplished, one way or another.
Almost imperceptible, a vibration running through the sand. Gone, then back again, a little stronger this time. He remembered the chant from the story of this desert.
The foot falls on the obsidian sands,
the hand knocks on the bone door
He had never truly believed the stories, but he had been glad for his hover bike keeping his feet safely above the black grains. He looked back, seeing his footprints stretched out behind.
Then again, stronger this time. Something was moving beneath the sands. The faces in the dunes still surrounded him, but now their expressions seemed twisted in anticipation.
Now the soft vibration had become a shaking, reaching up inside his chest through the thick leather of his boots. It grew, then stopped completely. From the sand in front of him, he could see a circular depression forming. He stepped back and drew out the comforting weight of his carbon fibre scimitar.
The desert surface erupted in a blinding spray. Lowering the forearm protecting his eyes, he saw the creature from the old tales.
His first impression was of a milky white pulsating vine growing through a strange collection of bones, steel, and armour. The white cords drew around and through everything, forming a thick column of torso. He could see ancient faded breastplates from empires that had disappeared millennia ago. Twisting out from the torso were two arms and four spider-like legs. Toward the end of the limbs he could recognise much more recent steel. The right arm finished in a curved blade much like his own. The right front leg was shorter, finishing in a shortened spinal column and two jagged bones. He could imagine his own hard tissue added to that limb- completing it. Reaching up from the torso the foreign objects finished. The twisted white tissue terminated in a gaping lamprey mouth. Ancient yellow teeth lined the insides. It lurched forward and the battle began.
His breath drew in and out raggedly as fought, trying to bring the pulsating neck within reach. He noticed that when the creature moved to the right, its weight shifted awkwardly forward, hampered by the shortened limb. He feinted to the right, then kicked out hard at the creature’s left leg, just before it made contact with the ground. It fell forward, the broken bones of its right leg scraping across the surface. He jumped up and plunged his sword towards its neck. It drew away at the last second, but still his sword penetrated the rotten white flesh, sending a thick gout of yellow blood hissing and splattering on the sand. A high-pitched whine filled his ears as the creature lurched back, limbs flailing. Half of a horned skull, freed by his blow, fell to the sand with a plop. The sand erupted in a second fountain as it retreated to the dark tunnels under the sands.
The faces faded from the dunes. Wiping clean his blade he resumed his long journey towards the distant column.
500 words exactly. Had to do some painful editing
this post is an entry in this contest by @f3nix