It looks like Cute Charm forces the PID to be a value between 0-255 (the gender value). That means 24 of of the PID's bits are going to be constant. Since three of the bits don't matter to shininess, that leaves only 5 bits to worry about. In other words, with the right ID\SID, Cute Charm could force shinies to appear with a 1\32 probability. EDIT: Seems to be for DPPtHGSS only. In 5th gen, PID generation works like Entralink generation, except the nature comes from a different frame.