Using Anthology names and all that jazz, this is what I beat it with just now. All characters were at level 41.

Bartz
Bare
$toss
2-handed
(mastered Knight, Sorcerer and Samurai)

Reina
Mimic
!White
!Blue
!Time
(mastered White, Time, Blue and Geomancer)

Krile
Mimic
!Black
!Summn
!Item
(mastered Black, Summoner, Geomancer and Mimic)

Faris
Ninja
!Sshot
(mastered Thief, Hunter and Ninja)

It wasn't optimised or supa-1337 by any stretch of the imagination, but then again it wasn't supposed to be. It got the job done.