When should WHM use Stoneskin I?

[Ghishlain]

Just to jump back to this for a moment. StoneSkin I is 266MP in the game, why the Wiki's say 399, I have no idea.

This is actually why I tend not to trust websites for specific MP costs anymore. I've noticed quite a few sites have MP and potency errors when I was trying to find a Potency/MP efficiency for Stone and Stone II and eventually just relied on the in game tooltip for the information.

Random tidbit of information - both Stone and Stone II have similar Potency/MP. If you're looking to conserve MP while adding a little DPS, Stone provides better MP efficiency for the same damage/MP (unless my math is horribly wrong)