There is no other way to get Magic Def Spheres from any other fiends (including no bribes either). One-Eye is unlocked after you capture x4 copies of every Eye-type enemy in Spira, which are all listed below:
Floating Eye (on the Mi’ihen Highroad) Buer (on the Thunder Plains) Evil Eye (in the Macalania area) Ahriman (on Mt. Gagazet) Floating Death (in the Omega Ruins)
What Are Magic Defense Spheres?
They’re a type of attribute sphere that turns an empty node on the Sphere Grid into a Magic Defense +4. This makes them pretty valuable, as Magic Defense is one of the most important stats in FFX – lots of enemies use magic attacks, and especially near the end of the game. And Rikku can also mix up Magic Defense Spheres too if you really want to. Here’s a few notable mixes you can try: Final Phoenix (Phoenix Down + Magic Def Sphere): Revives all KO’d party members to full HP. Nega Burst (Shadow Gem + Magic Def Sphere): Reduces all enemy HP by 3/4 Quartet of 9 (Amulet + Magic Def Sphere): One ally’s attacks and abilities will deal 9999 damage until the end of battle.
Are These Worth Farming?
Yes! Not only is Magic Defense one of the more important stats (trust me, you’ll notice the difference when you get it above 150). But farming One-Eye also comes with other rewards too. One-Eye drops Triple AP weapons frequently, which can be used in the Don Tonberry AP trick, and they also sell for a high price so you’ll be stacking gil too. Further, One-Eye occasionally will drop a Dark Matter or two instead of a Magic Defense Sphere. And Dark Matters are one of the hardest (and most valuable) items to farm in the game. So taking the time to farm out Magic Defense Spheres is totally worth your time. Sorry in advance, One-Eye!
