My:
Magmortar lv.X
Magmortar SW
Your:
Dialga X tin
Dialga DP
Dialga GE
I would do Magmortar X and 2 Candy for your Darkrai X (tin) and Empoleon X
Naah, then I'd rather go for 2 Darkrai X and add something small. Do you need anything small besides the stuff from your wants?