You can unlock Juggernaut by capturing five of each Ruminant-type fiend, which includes each of the following:
HP: 1,200,000
Juggernaut, just like the other Ruminant-type enemies, is powerful and does quite a bit of damage. Your best strategy for defeating it is to use 
Armor Break on it and to use weapons with the 
Piercing ability. Armor Break only has a 5% chance of landing successfully. A better strategy is to have Rikku use her 
Use Special Ability to use a 
Frag Grenade, which will apply the Armor Break effect 100% of the time.
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:
Lunar Curtain (x4) (common)
Shining Gem (rare)
Drops:
Strength Sphere (common)
Dark Matter (rare)