Halloween quest

[Shooterblade]

hello, after i finish the darkrai quest, he appeared with a text box telling me that he was weak and if i wanted to catch him, i went to the pokecenter to get my lvl100pokes but for some reason i couldent change my pokes from pc, i decided to take the risk and take the pokes i got from the dream to try and catch him, but he got burned by growlithe and rip me, but now i cant change my pokes from pc........, even tho i lost the drakrai its still bugged... can anyone at least let me change my pokes? (it would be amazing if i could try to catch darkrai again).