Pokémon X and Y Playthrough Discussion

Man, my Reuniclus got 4 Calm Minds off with recover stall and was ready to sweep. Then, a Glaceon crits me with Blizzard and I die in one hit. That's when I learned that stat modifiers mean absolutely nothing if they get a critical hit, so those 4 sp.def boosts were completely useless.

I need to rethink my strategy or not be so greedy with boosts...