Magic and Equipment
A lot times I hear the question: "Why does magic suck in FF2j?" Well, the answer is simple, it's your gear. Now you may be thinking: "What? What does my equipment have to do with my magic?" And my answer to that is: everything.
You see, your "magic damage" is based on your INT and SOUL stats. You may be thinking "duh", but let me explain. Once you equip something, be it weapon, helmet, etc., there may be a INT/SOUL penalty with it. Got your attention yet? Now before running off to see if I'm lying, let me tell you that it doesn't appear on your status screen. It's an in-battle effect.
Still don't believe me? I didn't at first, but try it. Here's my test:
Maria with INT of 99 and Lvl 16 ICE, fully decked out in Genji Gear, complete with Excalibur and a Rune Axe, did around 800-900 damage to a Sergeant. Next battle, same stats, only this time Maria is barehanded with only the Black Robe, ICE 16 did around 1600-1750 damage to a Sergeant.
The difference is almost scary, yeah? Check out each item's INT/SOUL penalties in the Items Section.