Nekagi
Eevee Fan
Some time ago, I played Platinum again and I saved before finding the roaming Mesprit. When I used a Master Ball to catch it, the nature was Sassy, so I reset the game, and it still had that nature (and I had to start ALL over again!). Does this happen to the non-roaming Uxie and Azelf before you catch them, or does this only affect the roaming Pokemon you come across?