The Doors of Trithius

Holding Right Bumper (RB) changes the face of many buttons. Your entire hotbar (1-0) is on the D-pad and ABXY buttons. Hold RB to make these, and other buttons, have a different action. Also, the Left Trackpad pulls up your masteries, skills, stats, etc menus. Just press up down left or right on it. If you hold RB and press up on the Left Trackpad, it will quick save (F5). Hold RB and press down on the Left Trackpad to quick load (F9). All the back buttons have functions.