Hay you shiny veeps, I have a question about EV spreads. Let's say I've got a tankmon, whose main purpose is meant to be soaking up hits in double and triple battles. The Poke in question is a magicguard Clefable with Follow Me, Cosmic Power, Moonlight and Moonblast.

If I want her to take as many hits of as many different kinds as possible, would the best route be to max out her EVs in both defense and special defense, or is it more effective to only max out one of those two while also maxing out HP? What's the benefit (if any) of maxing one defensive stat plus HP, as opposed to both defensive stats?

Thanks folks. I appreciate any and all wisdom.