This is a fiction contest by 
Damarthy is the paradoxical remnant of a gigantic megalopolis from Shintiara’s future. It is perhaps the greatest singularity of the whole planet.
A well-known saying in Shintiara goes: “If you don’t know what time you’re in, you certainly know where you are: Damarthy, the most ancient city of the future.”
The few that have overcome the difficulties of the intricate Canyons of Wind tell of a vast city with enormous glass buildings and inhabited by rough, primitive men.
These natives most likely live in the shelter of futuristic metal superstructures, the origins of which they don’t comprehend, which they nonetheless exploit to make simple tools and weapons by detaching fragments from them.
Mighty redwoods claim their living space, erupting from cracked cement and rising upwards as if in challenge to the artificial constructions.
This great vertical forest that invades every part of the city is home to different types of wild animals that contend for territory with the native populations.
There are some who swear that a mysterious sect of hyperhumans hides in the ruins, people who have evolved their bodies so unnaturally that they have completely changed into machines, but in the process they have lost their souls…
"Something move, skin prickly" Nal said to himself as he peered into the darkness. He was on night watch. He gripped his spear in the throwing position. He lived with his clan in a 50 story glass building in Damarthy. Paradoxically Redwood trees grew up through the floors, but the building remained stable, a tribute to its engineering. His hair was shaggy, and his clothing a rough robe.
Nal's eyes widened, he watched a slender humanoid being with translucent grey skin climb up through the floor on the redwood branches. The being faced him and spoke, but Nal did not understand. He shouted a warning and gestured with his spear, but the grey being walked towards him, expressionless. Nal threw his spear, and it struck the being squarely in the chest and bounced off. Nal's clan stirred from their sleep, awakened by the noise.
Nal grunted and charged. Nal rammed him it with his shoulder and the two tumbled to the floor. The being grabbed Nal's wrists and held them like a vise. Nal's strained his muscles to free himself, but failed. The grey being slowly spread its long arms wide until Nal screamed in agony. A loud clang rang out and Nal was free. The grey being was still on the floor. Nal's brother stood over it holding his war hammer, face contorted in anger. Nal backed away and Nal's brother continued striking until the being's head was crushed, then grunted.
Nal was panting on the floor. The clan gathered around to examine the strange creature. The skin was translucent but cool and hard to the touch. The facial features were humanoid but undeveloped. A small straight line of a mouth, a flat nose, and small lidless eyes. Nal's brother lifted the body, walked a few steps and threw the body from the building. The body fell 34 stories and landed with a sickening thud below. Nal crawled painfully to look over the edge. His pulse quickened, the moonlight revealed dozens of grey beings surrounding the fallen one, and... eating it. Some were looking up. Nal told the clan, and they prepared for battle. They sent the women and children to the top floor, and blocked the stairs and branch holes in the floor.
They didn't have to wait long, long slender arms were pushing through the blockade, and Nal's clan fought back savagely. The grey skin was impervious to edged weapons, but blunt objects worked well enough. When silence fell the clan had thrown down 32 grey ones, but when Nal looked down again, the bodies were gone. He tried to celebrate the victory with the others, but in his heart he knew it wasn't over.