I don't really know what's up with the game consistently referring to Garula as a singular creature, when there are ostensibly several of them - the one in Walse, the ones in random encounters, and this one - but it's odd. We also appear to be in a typical "peaceful animal warped into aggression by an evil influence" scenario, and I suspect that influence is borne by the meteorites. "Evil sends meteorite, influence seeps out and seeks a nearby monster to take over" would be a reasonable explanation for events thus far.
We're told the King went after Garula, but not just the King - "some soldiers I've never seen before" as well. An unknown party acting as crystal protectors? Fascinating.
My takeaway, and I can't recall if there was any animation support or whatever, has always been that Garula really is just a single animal, and you're simply wandering around and running into it and scaring it off when you 'kill' the random encounter ones.
Berserker (this appears to be a big beatstick type of guy that is constantly under the Berserk status effect?)
Mystic Knight (this job has a 'Spellblade' ability that says it enchants a weapon with a spell I know, though I don't know the details on what this actually means in practice)
Time Mage (this job has those spells from earlier, buffs and debuffs like Slow, Regen and Haste)
Summoner (I assume this works like in FF3)
Red Mage (it can cast both White and Black Magic up to level 3; I am being told that the real payoff of Dualcast takes like twice as much time as mastering any other job, so I'm not sure about committing to it for the entire rest of the game)
So!
I'll be thinking about how to build my party for the next stretch of the game, but I appreciate advice and input as long as they don't go into spoilers. I like Time Mage as a thematic thing, Mystic Knight looks really cool even if I am not quite sure I understand how it works, I need to have a Summoner no matter what as a point of principle, I wanted to do Red Mage Vergang but it's looking impractical, all in all a lot to think about.
Berserker is technically a very powerful physical attack choice at this stage, but there's only a couple of places this could really matter as useful honestly. It's stats are worse than a monks for passing to Freelancer, and it doesn't give any particularly notable abilities in my opinion.
Mystic Knight works like so: you cast a spellblade spell and for the rest of the fight (or until you die or cast another one) your weapon attacks are imbued with the spell.
What this actually means is depends. For damage spells, it does nothing unless the enemy is vulnerable to the element the spell has, in which case it acts like hitting the weakness but often with further caveats. For example, Blizzard will cause your attacks to treat ice vulnerable enemies defense as zero and also do double damage, Blizzara will cause the same thing except triple instead of double damage, and Blizzaga will cause the enemy to instantly die unless it's internally tagged 'heavy' (mostly bosses, but some standard enemies as well) in which case it 'merely' progresses to 4x damage multiplier (and still treat defense as 0).
For status magic, it attempts the status on attack. If the enemy is considered
vulnerable to the status, it always works. There are cases of bosses with vulnerabilities like Sleep and Silence that can be puzzle fight shutdown more or less entirely by this means, but obviously you need to know (or guess) the specific weakness to do that particular trick.
Note that most Mystic Knight 'spells' do not benefit from the magic stat, due to modifying physical attack damage.
Also note that Mystic Knight spells are all a variant on an existing spell,
and are not acquired separately. You can use the blizzard blade spell if you have blizzard, and when you eventually get blizzaga, you'll be able to do blizzaga blade just for that. They're a mix of spells from, if I recall right, time/black/white, weighted heavily towards black.
Time Mages are weird. Primarily, they're a buff/debuff mage, but they also have a lot of weird utility spells. Comet and Meteo go here, not in black, and are the generally best single target kill spells for when available. (meteo is like, the best single target spell damage in the game if I remember right). They're plenty decent but how useful you find them is gonna partly depend on playstyle.
Summoner is a lot like Final Fantasy 3, yes, in the sense that most summons are an automatic party wide attack, though some later provide buffs instead. As a general rule, summons are superior to black magic for crowd control, but inferior for single target damage- Blizzara has an attack of 50, which is cut in half on a mass cast, while Shiva (not really a spoiler, I think, to admit Shiva does ice damage) has an attack of 38, but is always mass cast at full strength.
Offensive summons usually bypass reflect, as well. Further, Summoner has the single highest magic score- anyone you want to be a caster in the late game will benefit from mastering Summoner at some point.
In the short term Red Mage could be used to make a snazzy arch-mage deal. After all, the RED command could be given to a summoner to get your currently available black AND white magic, and with the Summoner's superior modifer. Red Mages are pretty weak in stat lineup though, and yes, going for Dual Cast is the main appeal longhaul, which lets you cast two spells in a turn (anything Red level 3 could do, or anything else your character currently has a magic skill for, eg you can dual cast sumoners.)