A Let's Play of FFX-2 I watched had the creative idea of trying to help Brother, because clearly there is something seriously wrong with him. The LP'er put in a variety of Brother's symptoms into WebMD to see if they could diagnose just what sort of ailment has befallen everyone's favorite Blitzball star since the last game. Closest thing that seemed to fit was Head Injury.
What say you all? Was it the drugs? The guy does seem to be tweeking pretty hard in the game.