To be honest, all I did to create the torso shell shown was paint this piece with a pale summer sky blue color; the inner workings of the torso are relatively similar to the structure of the parent set, sans the addition of the 4M axles to anchor in the chain and the system component to attach the Noble Huna piece.
If you would like more info on how to build creative, functional, poseable, and aesthetically pleasing MOCs, you can check out this topic on our message boards.