Legion Emblem Managers will allow the Legion Brigade General to change a legion's emblem. Talk to <Garun> in Pandaemonium or <Inofe> in Sanctum.
Once a Legion reaches level 3, they are allowed to register their own custom emblem. To change or register your Legion's emblem, it is necessary to first create your own custom design in whatever editing or painting program you see fit. Your final design must be sized down to 256x256 (24 bit), and the format must be either the .BMP or .TGA extension. To register your emblem for the first time, place your Legion emblem file to upload into the AION folder and press the YES (CONFIRM) button.