I believe the probability is about 1/4000 or so, and yes, Beldum shiny it is possible
Anyone else got super buggy with Swablu? Trying to catch him, aerial slash will not let the battle advanced (it erased my battle hud) and sometimes baby-doll eyes gave me the same efect (against Yior).
I am at her currently, Gallade and Lucario will require a grind definetely
