Nice to see Ring Magic. Death! I'm loving it: it's a classic FF spell that I always liked using and it actually fits the whole Lucis culture.
We've already seen (in KG) instances of other spells that could be done with the ring (Protect, maybe? I'm guessing Cure could work, too?). I wonder what else is there. Unless is a contextual thing (like Summons), I guess we should have, at the very least, around three different kinds of spells, as they have their own slot in the menu and it'd be weird if we only had one or so. Maybe it's a random thing. Or maybe it can only be used during XV's version of Limit Break (the Armiger).
Oh, and what about Regis and Nyx' abilities to use fire just like that, without using the pokeball? I don't know if that might be Ring Magic, something else, the representation of Elemental Magic in the film or just nothing.