Thief to me is just not worth it. While I will agree that the Black Mage is utterly useless in the original NES version due to all the magic bugs and how unbalanced the Red Mage's magic set is, in any port/remake that fixes the bugs, the class is actually pretty good. Thief on the other hand is garbage in all the games and the only reason to bother is to get the Ninja class which I frankly didn't feel was so wonderful it deserved me playing with a handicap for a good third of the game.