Suggestion: Mounts based on FFXIII Eidolons

So I was watching a video on youtube about the evolution of Shiva over the course of the entire Final Fantasy franchise and I was reminded of the eidolons in FFXIII. Each of the six summonable eidolons have a Gestalt Mode in which they would transform and become ridable by the character that summoned them.

I understand it would probably be very hard to work them into the game to be obtainable in game, at least not without making some kind of FFXIII related event or raid/trial series in the future. That being the case, even if they were only available on the mogstation, I'd love to beable acquire them as mounts to add to my collection.