Sure.
By any chance, did you check out the IVs on your Darkrai? Mine is... well... bad. HP is middle range, Speed was actually pretty high, and everything else was rock-bottom. Zeros across the board.
Well, it's not like I was planning on using it any way, but still... Ah well, at least I have one. Now to just find someone with a spare Celebi, Lugia, Ho-oh, Arceus, and Shaymin.
Yeah, like that's going to happen.