The Mage primarily uses elemental magic to attack, but can also do things like put enemies to sleep or teleport the party. Has the highest passive magic power bonus, but also extremely low (lowest?) HP. Enemies in the second half of the game tend to have high resistances, so some planning may be required to keep the mage effective. However, utility spells that don't require a resist check (like teleporting) are still very useful, although other classes other than Mages can learn those too.
Basic Skill: Mage Spells
Mastery Skill (level 26): Magic Spell Power UP+1: Magic power increases significantly with level, up to 737.6%.
Starting Class: A. Mages learn mage spells the fastest (useful for class changes), and mage spells are very useful.
Ending Class: B. With EX Skills they're not as irreplaceable as before. Supposedly after level 2000 they can single-shot entire parties.
No Class Changes: C. Magic is in limited supply unlike physical attacks, so being a one-trick-pony may not be worth it, especially with limited access to Innocent gear. With the proper party and EX Skill setup, it's definitely doable, but it might be worth learning other magic first and class changing to a Mage later.
- I guess there's a specific spell (Musukai?) that can instant kill mages. Not sure if this is to discourage people getting all the magics on all their party members? (I don't see anything on the JP wiki about this. Mistranslation? Confirmation needed.)
- Obviously, magic-enhancing EX Skills are useful for Mages. High Magic Source is essential for countering enemy barriers (and potentially killing your party with a reflected high-power spell), but it's better to have a different party member take High Magic Source, and the mage take Spirit Contract or Magic Essence instead.
- Most Mage weapons are weak or have short range, so the Mage may spend a lot of time defending when MP is being conserved or is exhausted.