Let me get this straight...From what I can tell, shields don't give you passive defense stats, correct? Their defense power (be it ele, norm, etc.) is only activated when you're...shielding? I know it sounds painfully obvious, but I just want to be sure. I guess it just bothers me that only two items (helm and armor) offer passive defense.
The defense on shields indicate which sort of attacks they can take more of a beating from before they break. The defense from shields don't actually ever add to your defense basically imagine whenever you're shielding that your shield has it's own little health bar that decreases when it gets hit and the damage to it is reduced by it's defenses and when the shield's HP reaches zero it breaks.