Billy was a soldier in the Slayheim Liberation Army along with Brad Evans, and served under Vinsfeld Rhadamanthus. At the end of the war, however, Billy was critically wounded, making him an invalid. With the close of hostilities and the destruction of Slayheim, he was left in the care of Merrill in the village of T'Bok.
Once Brad Evans can return to T'Bok, he begins to understand the true meaning of courage. This, in turn, gives him the spirit of the guardian Justine. Billy is also shown at the end of the game, talking, cheering Ashley Winchester on as he battles Lord Blazer one last time. The suggestion is that Billy has indeed recovered, but the game's awful localization effort makes it impossible to tell.
Brad Evans has developed a reputation within some fan circles as being a gay character icon, based largely on a misreading of the poorly-translated dialog between him and his brother in arms, Billy Pilder. Billy and Brad developed a deep friendship as brothers-in-arms during their time in the Slayheim Liberation Army, and there is no question that their relation ship is close. However, this is simply keeping with the fraternal closeness commonly found between fellow soldiers in wartime and was not meant to imply a romantic relationship.