How to get Sephiroth's Vision in Final Fantasy Resonance

As you play Final Fantasy Resonance, you may be wondering where Sephiroth's Vision is. You can see it in the menu, greyed out, and certainly the iconic antagonist from Final Fantasy 7 wouldn't just be found in a shrine like the rest of the Visions from other games. Well, you're right. Sephiroth is somewhat hidden, though to unlock him, you'll need to actually defeat him as a boss.