Purpose: An elaborately designed, but powerful CPS sidearm, where performance and usability are foremost, and cost is a secondary factor. The blaster uses cylindrical CPS to minimize dead space, and the reservoir and PC case are one and the same. The reservoir however, is larger than it appears; it covers more than just the tube and goes around various nooks and crannies in the blaster to make full use of the space. The tube is there to guide the cylindrical bladder. However, the actual boundaries of the reservoir have not been specified, and I should probably do so on the next revision.
The PRV method (which is used in every bladder-powered automatic Nerf blaster that I know of) is more for usability and ease of pumping than for cost saving. The nozzle selector is unnecessarily complicated, but hey, it looks better. It was inspired somewhat by the CPS 1500/1700 design but I decided I wanted a 3rd nozzle, but left the rest of the layout as is. Nonetheless, a revision to the standard nozzle selector would probably be a good idea.
Filling system not specified; twist and turn valve or cap is ideal. Originally I was thinking of a spring loaded seal to keep water out, but pushing on it may inadvertently cause water to flow out. The reason it is positioned where it is instead of at the top (the conventional location) is to accommodate backpack attachments, which can give the blaster enough waterpower to be used as a primary. (The only inhibition being small PC size, close to that of most stock PC's.) The bladder is stretched more heavily than other blasters in order to be able to expel more water.
The ball valve does not have to be lubricated, like most stock valves eventually do. It can probably be treated with a long lasting lubricant when manufacturing to maintain reliability. The high torque push spring ensures the valve is pushed back even if it is stiff. (By the way it is designed, the spring has to be very stiff and counteract with far more force as it is acting on the shorter end of the arm that opens the valve.)