You can unlock Greater Sphere in the Monster Arena by unlocking two of the Species Conquest fiends.
HP: 1,500,000
The most challenging aspect of the battle against Greater Sphere (which is similar to that of the Earth Eater) is that it will counter all attacks against it with 
Ultima. It also has an attack called “Hydraulic Press,” which will reduce each party member’s HP by a fraction of 15/16 or approximately 93.75%.
Greater Sphere is a pain in the ass to defeat. Your party members will end up dying a ton because there is no way to prevent each of the counterattacks. Just make sure that each of your characters has the 
Auto-Phoenix auto-ability and that you have a heavy stockpile of 
Phoenix Down. Consider also using 
Auto-Life as well to keep your party members alive. Aside from that, there isn’t much strategy involved…
You should consider power leveling your characters and obtaining the Celestial Weapons. Check out the Advanced section of the Tips and Tricks for more information. With properly leveled characters, this fight is pretty straightforward.
| Ability | Description |
|---|---|
| Sensor |
“Immune to sensors.” |
 Scan |
“Immune to scans.” |
Steal:
Gambler’s Spirit (common)
Return Sphere (rare)
Drops:
Luck Sphere (common)
Dark Matter (rare)