Hit 25,000 RE's in Dragonspiral Tower today and decided to give up. Clearly nothing there wants to shine for me, so time to move on (at least for now). I'll go back sometime, I refuse to give up on a hunt that I spent so much time on. Anyway, I've decided to start MMing for a Shiny Larvitar instead. Spent a good hour and a half breeding a Larvitar with Pursuit, and then finding a female Japanese Larvitar on the GTS. So now that everything's all set up, time to start collecting and hatching some eggs! If only they didn't take so damn long to hatch, but oh well. Good luck to everybody else.
EDIT: Just hatched my first 30 eggs, and in this batch there were three Adamant Larvitars, and SEVEN Larvitars with 31 Attack IV's, including an Adamant female with 31 in both Attack and Special Defence. Lolwut? Not really sure how I got so lucky as I wasn't using any of the power items or an Everstone yet, but hey, I'll take a little luck after the epic fail in Dragonspiral Tower.