Yay, I'm a strong princess!
Obviously on paper Electric-types, Gyarados and Special Landorus are easily the biggest problems, but it's more of a "who sets up first wins" sort of ordeal. I would say Breloom /could/ be replaced for an SR Celebi with something like U-Turn - Earth Power/HP Ice - SR - Leaf Storm to help fix this, but I mean it's offense, you can't check everything! Oh and then put Thunder Punch on Jirachi. Luvdisced.