We’re near the release of Final Fantasy X/X-2 HD Remaster and there’s no reason to keep the Magus Sisters a secret. Yuna can find this Aeon off the beaten path in the Calm Lands.
Final Fantasy X HD has the Expert Sphere which was added to Final Fantasy X International and the PAL version. This sphere grid gives players more customization options from the beginning since all of the characters start in the center relatively close by to each other. This grid also has extract abilities that basically act as the Sphere Distillers from vanilla Final Fantasy X.
For more about Final Fantasy X and the origins of Blitzball read our interview with producer Yoshinori Kitase.