Major Rand Banion was an Army Special Forces Operative with four years of combat experience and the hero of multiple missions. He was absolutely fearless, no mission was to tough and he had a zero percent failure rate. He was the army's logical choice to become Project X-O's new user. The X-O Manowar armor had fallen into the US Army's hands during World War II and had been trying to unlock it's secrets for over 50 years. When the terrorist group R.A.G.E. targeted the four targets (the last the White House) Band insisted he be bonded with the armor immediately. Despite flat-lining the bonding worked and Banion became the first American X-O Manowar.
During his first mission Banion began testing all of the offensive and defensive abilities the Manowar was capable of on the R.A.G.E. attackers. (Note while Doctor Wylie was able to figure out many of the secrets and how the defensive mechanism worked, he could not test the weapons as only a host could do this).
When Banion decided to attack the command ship he discovered the armors fatal flaw. The armor's defensive mechanism responded to the users self preservation instincts. The main one being fear. Because Banion didn't know the meaning of fear, the armor did not adequately protect him and he was killed by a particle beam blast.
Donovan Wylie took the armor from the now dead Banion and after initially refusing to bond with the device finally did so becoming the next X-O Manowar.
It wasn't until issue 18 of the series that Wylie learned that the X-O armor retained certain aspects of its previous wearers. Rand Banion, despite only being bonded for a very short time, was also in the X-O Armor and he would converse with Wylie from time to time (until the series ended 2 issues later).