Hello everyone ! i just started working on my concept to participate in this contest today and ill be sharing my work in progress in this topic 
Im not a concept artist but ill be designing my own concept and idea for this contest . 
i started gathering references about my subject and ideating in Zbrush , while i develop a story for it simoltaneusly , so ill be tweaking the concept as the story gets clearer. 
here is a screenshot of what i have so far . its a very rough sketch and first steps of designing my characters .