Speaking of RPGs there should be a Smash one. Now that would be fun
What type of RPG are we talking here?
I think a strategy RPG would would.
There are so many characters, you'd want to use as many as possible at once.
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Update on my GS Playthrough
Stopped playing for now, this is what the Djinn set-up looks like:
I'm currently in Xian. Ivan's holding the Douse Drop and Isaac has the Catch Beads and Orb of Force.
Mia's hogging all the Water Djinn. At least everyone else can share.
Isaac got Gaia early, interestingly enough.
On the offensive side, Garet has nothing but single target Psynergy right now. Specifically he has Astral Blast and Volcano. Isaac also has Astral Blast.
This means Isaac and Garet are both capable of shooting giant stars at people, and causing massive explosions (of Planetary Energy and Volcanic Activity, respectively). They both also have Debuff and Status Psynergy, though Garet can also bestow a Buff.
Ivan has Growth and Bolt and their second levels, along with Cure and it's second level. He's the most versatile member of the party right now,
probably because he doesn't have any like-element Djinn on him.