All the FFs have been shattered into little pieces and you get to build your own Frankenstein monster FF title. The rules are simple, you have to choose the story, cast, customization system, battle system, sidequests, worldmap/cities, and music to build your game but you are only allowed to choose one aspect from a game, so if you choose VII's story, you can't use anything else from the game for the other category so for example:
Story - FFIV (Crystals and the moon)
Cast - FFVIII (Squall and Rinoa)
Customization System - Crysterium (FFXIII)
Battle System - Turned Base (FFI-III)
Sidequests - X-2's silly nonsense
Worldmap/Cities - FFVII (Midgard baby)
Music - FFIII
You can either take this serious and try to build an ultimate FF game(just don't think too hard about it, and run with it) or come up with some of weirdest pairings you wish. Maybe Squall and Rinoa could have shined better had it been about IV's cast and set to FFIII's charming music set in Midgard.
Template:
Story
Cast
Customization System
Battle System
Sidequests
Worldmap/Cities
Music