This is the end result of combining Optimus Prime, Jetfire and Overload into a massive super robot. Optimus Prime forms the upper body; Jetfire the legs, and Overload fits over Prime's shoulders as heavy weapon pods. Their vehicle forms interact as well, with the Prime truck being able to pull the Overload trailer which can carry the Jetfire space shuttle.
The combined form of the Universe Micromaster Aerialbots is Superion, an amalgamation of six robots plus their pack-in accessories that serve as connectors, head, and extremities of the gestalt warrior. While in Japan, the original source of the design ( Sixwing , 1992) was available in a collected set, this combiner needed to be purchased one bot at a time in the 2007 Universe release.
