Quote Originally Posted by farplaner
As a rule, I always steal as much as possible with Zidane from the beginning of the game. Each successful steal increases the damage done by thievery (gamefaqs can give you the formula). By the time you get to Ozma it should be no problem to have max damage with Zidane.

As Chris quoted, even with the best of everything there is still a little luck involved to survive Ozma.
The formula for Thievery is [Speed/2 * # of Successful steals], thanks to Shotgunnova.

The only times I ever stole was during boss battles, so my Zidane's Thievery only does like 1,100. Even if I did have enough time to spend hours on end stealing, it would just be too boring and dull.