The Wing Gundam Zero's raw power, and the dangerous stress it would place on its human pilot, so frightened its creators that they never completed their work. For fifteen years the Wing Gundam Zero existed only in blueprint form, a base design from which each of the five scientists developed his own Gundam for use against the tyrannical Alliance. In AC 195, unfortunate circumstances placed Gundam Sandrock pilot Quatre Raberba Winner in space without a Gundam, with a dead father, and with enemies of the very space colonists he was fighting to free. Wracked by a serious mental imbalance, Quatre discovered the abandoned work of the five scientists, and he built the one of the most dangerous mobile suits.

This mobile suit was was a design to truly be feared. In addition to being extremely maneuverable, it sported Gatling-like machinecannons, beam sabers, and an extremely powerful twin buster rifle, capable of wiping out entire groups of mobile suits in a single shot. It also sports a set of four angelic feathered wings. Fanciful though they may look, these wings still contain an array of powerful vernier thrusters. They also lock together to form a heat shield, protecting the Wing Zero during atmospheric re-entry. However, one more factor put the Wing Zero above everything else: the cockpit's "Zero System," which allowed the pilot's mind to interface directly with the Gundam's combat computer. Although the exact nature of the Zero System's operation is unclear, it appeared to operate by "sampling" the pilot's thoughts and, combining them with current combat data, presented the pilot with various alternate outcomes. Thus, depending on the pilot's mood, the Zero System could tell him or her how to achieve total victory or decisive defeat.

Source: Gundamproject.com, Gundam W: Endless Waltz DVD