Sorry if this idea has been forwarded already, but I was thinking since we are getting Triple Triad soon, what about "Blitzball" as another mini-game?
I for one, honestly loved that mini-game, spent many hours on it.

I was thinking maybe a versus mode via the pvp duty finder?

I personally think it would fit in well with XiV, I'm sure you can conjure a way to make a big ball of water you can breathe in, with the magic in XiV