A small world, cosmic afterthought to the likes of the massive Bomthain and pleasant Esseles, Shella spins through space as a half ignored member of the Esseles system. Barely large enough to qualify as being a true planet, it formed from the more porous elements circling the Esseles star in the ancient past, resulting in a poor world in almost every sense of the word. Few elemental gases existed in the materials which collected to form it, and those that were present have remained locked in the material of the thick but porous crust of Shella .

Without an atmosphere to protect it, meteor impacts which would have gone unnoticed on the other worlds in the system instead resulted in a pattern of overlapping impact craters across the breadth and width of the surface. Ranging from the centimeter wide seas of "Crater rain" from when Shella crosses the path of Bomthain twice a year, all the way up to the continent sized Primecia Impact Event in the northern hemisphere, craters of all shapes and sizes form the chief source of topographic relief on the otherwise barren surface of Shella .