The New Classes

With the TAIL in hand, return to BAHAMUT in Cardia. He will reward you with the Class Change, which will upgrade every party member with new abilities. Statistically, there aren't any changes aside from newly gained MP for the KNIGHT and NINJA. (Actually, the MASTER is an exception to both of these rules: they gain no new abilities over a Bl.BELT, and in fact get a statistical downgrade for their Magic Defense. Don't worry, they're still amazing.)

KNIGHT

As a KNIGHT, your FIGHTER fills the same role only more so. Their role won't change, but they will be able to use the best weapons and armor you'll find during the last few chapters of the game. They can also learn white magic of levels 1–3. They can't learn HARM spells, and in fact the only spell level where they even need to choose which spell to skip is level 2. At this point, any choice is fine. The KNIGHT's spell slots are best used as extra CUREs (and CUR2s), though RUSE is also fun to use. The KNIGHT needs to gain a level or two before he'll gain spell slots, but the spells are so cheap that you may as well buy them all right away.

NINJA

Of all the classes, THIEVES get by far the biggest upgrade from the Class Change. The NINJA can use most weapons and armor, with the exception of the top-end KNIGHT gear. Since most of that gear is unique, the NINJA will end up about as well-equipped as a second FIGHTER would be. He still isn't as proficient in combat, but he gains full access to level 1–4 black magic, including FAST. Having an extra FAST caster can speed up your early-battle buffing, and the extra spell slots are nice as well. There really isn't anything else a NINJA is liable to want to cast, except perhaps SLOW.

MASTER

As stated above, the MASTER gets nothing from the Class Change except a nice new sprite and a Magic Defense downgrade. That's fine, since the Bl.BELT was already kind of overpowered. At really high levels (beyond anything you need to finish the game), the Bl.BELT/MASTER's damage potential is well beyond any other class's.

RedWiz

The RedMAGE starts the game off as a very powerful character, but quickly begins tapering off. Unfortunately, the upgrade to RedWiz does nothing to stop that. The main advantage the RedWiz gains is access to important utility spells. LIFE and EXIT are the most important of these to pick up. LIT3 and ICE3 are also nice additions to the RedWiz's spell list. Finally, the upgrade allows them to use some of the near-top-end gear you'll find in the game's last few dungeons. Don't expect much out of a RedWiz in combat unless you give him the Masmune, though.

Wh.Wiz

In terms of gear, the Wh.Wiz doesn't get much over the Wh.MAGE. Really it's just the Thor Hammer, which is better off used as an item than used to hit things with anyway. Their big advantage is access to new spells, the most important of which is EXIT. CUR4 is also a nice upgrade, and at level 25 you'll want to pick up LIF2, FADE, and WALL.

Bl.Wiz

The Bl.Wiz doesn't really gain anything eye-opening from the Class Change. They can now use the CatClaw in combat, but they shouldn't be attacking anyway. A number of KO spells also open up, but they are often not worth the effort. The biggest prize is NUKE, which a level 25+ Bl.Wiz can cast.