Well, there goes Cleyra. That Odin summon was badass.
Are summons and eidolons one in the same or...?
Summons are called differently in different games, "Eidolons", "Aeons", "Guardian forces", etc. Although some terms are re-occuring.
The Odin summon is one of my favorite moments of any game ever, because at that moment it's like the story changes, It's not a coincidence that it looks like a nuke, because that moment really is like the Hiroshima of FFIX, until then you were having this midevil adventure with swords and magic, and then suddenly a freaking god appears and war is just changed for ever. The implications are huge and the game knows it, it lets that sink in.
One of the things I don't love about FFVII is that the fact that people are able to summon literal gods has almost no story implications, not in IX, in IX, summons...are....huge.
FFX also gives proper importance, however, and I can say this without spoiling, that's how minor it's presented imo. In FFX you see your first summon very early, and in a cutscene that really isn't that grand.
Not in FFIX, it takes an entire disc before the first time you see one, you just get teased, they're right there in Garnets ability list, beckoning, just out of reach with gigantic mp costs. And then when one finally is summoned it just absolutely changes everything, everytime a summoning show up in IX its' serious fucking business. Which is what I mean when I said FFIX has the BEST choice in cutscenes.
Its' also the moment you may start to realize that FFIX is perhaps a bit darker that you'd initially expect, sure, we already had Vivi's existential crisis to deal with, but we just had our second genocide in a matter of hours. Also, not everything goes the heroes way, it's not a series of victories, it's depressing failure after failure, first Burmecia, now Cleyra, losing the battle, in the hope that eventually there will be a happy end.