Unlockable: Onion Knight
To unlock the Onion Knight as an option for any given character, that character must be a level six Chemist and a level six Squire.

Hint: Friendly Fire & Chocobo
If you have a Chocobo in your party, you'll no doubt know that they have Choco Cure, a useful skill that can be used over and over again. Choco Cure restores some of the Chocobo's HP, as well as characters in front of it, behind it, and to the left and right of it. If you try executing the hint entitled "Friendly Fire", having a Chocobo in your party to heal characters grouped together each round will allow you to survive the fight even longer, building experience and JP levels even higher.

Hint: New Jobs
There are two new jobs in this release of the game that weren't in the original PSX release - Onion Knight and Dark Knight.

Hint: Job List
Below are a list of all of the base jobs in the game, and how to unlock any given character's ability to use said job.

Archer - Squire (Lv. 2)
Arithmetician - Black Mage (Lv. 5), Mystic (Lv. 4), Time Mage (Lv. 4), White Mage (Lv. 5)
Bard - Orator (Lv. 5), Summoner (Lv. 5)
Black Mage - Chemist (Lv. 2)
Dancer - Dragoon (Lv. 5), Geomancer (Lv. 5)
Dragoon - Thief (Lv. 4)
Geomancer - Monk (Lv. 4)
Knight - Squire (Lv. 2)
Mime - Chemist (Lv. 8), Dragoon (Lv. 5), Geomancer (Lv. 5), Orator (Lv. 5), Squire (Lv. 8), Summoner (Lv. 5)
Monk - Knight (Lv. 3)
Mystic - White Mage (Lv. 3)
Ninja - Archer (Lv. 4), Geomancer (Lv. 2), Thief (Lv. 5)
Orator - Mystic (Lv. 3)
Samurai - Dragoon (Lv. 2), Knight (Lv. 4), Monk (Lv. 5)
Summoner - Time Mage (Lv. 3)
Thief - Archer (Lv. 3)
Time Mage - Black Mage (Lv. 3)
White Mage - Chemist (Lv. 2)