This page lists the units in Final Fantasy Tactics Advance not based on a job, but instead a character. Most of these characters come from other Final Fantasy games, although some are instead from various other games promoted by Mobage at the time. Note that the details of the former type are listed on the character's own page, the details of the latter (for lack of a character page) are found here.
See here for a full list of the available FFTS unit pages.
FF Characters
Agrias Oaks (FFT)
Agrias, the Holy Knight (SR)
Auron (FF10)
Auron, the One-eyed Parivir (SR)
Balthier (FF12)
Balthier, the Sky Pirate (SR)
Jecht (FF10)
Jecht, the Final Fighter (UR)
Tidus (FF10)
Tidus, the Visiting One (SR)
Y'shtola (FF14)
Y'shtola (SR)
Yuna (FF10)
Yuna, Summoner from Another World (UR)
Other Characters
Lockburke

Name: Lockburke of the Seven Heroes / 七英雄ロックブーケ (SR)
Job: Seven Heroes / 七英雄, Race: Demi-god / 亜神
Cost: ?, Recommended Row: back, Type: Magical, Anti-air, Element: Dark
Stats (lv 1): ?
Stats (lv 60): HP 406, ATK 479, DEF 249, MDEF 249, SPD 98
Attack: Holler
Ability: Temptation
Starting Equips: Rod, Robes, Steel Ring
Description: ?
Obtain: Emperor's Saga collaboration campaign
Succubus

Name: Succubus / サキュバス (R)
Job: Familiar / 使い魔, Race: Demon / 魔種
Cost: 3, Recommended Row: back, Type: Magical, Anti-air, Element: none
Stats (lv1): ?
Stats (lv50): HP 185, ATK 171, DEF 127, MDEF 127, SPD 295
Attack: Magick Bolt
Ability: Fall in Love
Starting Equips: Knuckles, Leather Clothes, Steel Ring
Description: So we meet again, mister Clan Master. This too is a dream in the night. This means you fell into my trap again. Heh heh heh… I won't let you escape, mister Prey. …n, what? You're moving? …wai-! No…! That…don't touch the tail~~~!
Obtain: Lord of Vermillion collaboration campaign, limited-time Hero Summon
Category: Jobs