Okay D_S That's amazing luck. I guess I really need to punch it to get Palkia before you do. If anything you remind me of having Missingno. Masters luck on these shinies.
Yami, I'm sorry, but you have to locate Cresselia in the wild first. Why don't you just catch Mesprit, save your game, and then soft reset for Cresselia? That's what I would do if I were in your situation.
I think I'd have a bit more luck if I had time to hunt like D_S does. School work is pain this year.