Agreed. If you want to spend lots of MP for minimal benefit, try Shield. Or if you don't want that but insist upon filling that Materia slot, use W-Item for X-Potion and Turbo Ether in one turn. Or use an Elixer. I could go on.

OOC:Going back to Shield: it'd actually be a great spell if you could A) cast it on more than one character, B) have it last longer, C) cost less MP, or D) all of the above. Too bad.