Hmmm....never caught Latias until Gen IV, and it's a let-down now it's banned from OU battling...
Jirachi's not that cool, tbh.
I'm going to go with Registeel, as I solved his puzzle using the braille, rather than just looking on the internet. I'm so proud of myself :D I love that trio, and whilst he doesn't have the best design, I like their master, Regigigas, aswell.