I'm sure I'm not the only person to discover this, but I want to share it with anyone who hasn't farmed the pack-man maze ghosts of mirage for their animus- THESE GUYS ARE AMAZING!!!
So, they are not the easiest to beat- you can only attack every 5 turns, but that actually helps you set up into a very comfortable rhythm. NOW, why do you want them?
They are indestructible. Totally immune. You summon them and they deal steady damage and take hit after hit... These guys have been key to my ability to solo countless dungeons. They can't die. They're AWESOME.
Check them out and give them a shot- they're you're best friend when no one else is around!