Here is an interesting idea for geomancer that was said on my gamefaqs thread:

"basically the idea was that a geomancer drops elemental fields around the battlefield; when standing in those fields, the properties of their attacks change. so in a way it's like positionals, but rather than their positionals being dependent on where they're standing in relation to the mob they're hitting, they're dependent on which of their elemental fields they're standing in"