I went the magic casters path in this game.

The armor that Relm can equip can make her invincible to magic. And putting a Genji Armor set and a Force Armor set on Celes and Terra makes them nearly
invicible against magic attacks too.

Our Mblocks consisted of

Terra: 59%
Celes: 79%
Relm: 55%

There are a lot of items that if paired to already magically powerful characters... it can make some major magic stats.

But I use

Terra
Celes
Relm
and
Locke

because Locke is the luckiest character.

I use to use Gogo cause he could mimic the 3 magical maidens spells, plus, could use any of the spells they knew on his own. =/ But Locke is my choice.
Although I still say GOGO is very neat.