I don't know why but I am reminded of korra with the whole order(light)/chaos(dark). Real world (eorzea)/ spirit world (void). Perhaps its just a waxing and waning between a hydeline controlled world and zodiark one. That warriors of light (there were more than 1 in 1.0) and warriors of darkness (should be 13 total)

I am guessing it'll be the cliche darkness isnt bad, but is necessary and that its the ascians the corrupting darkness.

Still where do the elder primals fit into all these?