This thing uses a lot of attacks, more than I know of, but I'll list the pair I do.
Exhuviation- Restores some HP and removes one detrimental status effect from the mob. Acts somewhat like Erase for the mob- I've had it shrug off Frost, Shock, Dia, and Bio when it uses this move. It restores roughly 1/10th of the monster's total HP when it uses it.
Erosion Dust- AoE damage attack that also inflicts a very, VERY hard hitting Dia. Something like 30 HP a tick. The attack itself usually does around 110-120 to a level 75 character, and then the Dia...Fortunately, the Dia effect doesn't seem to last very long. However, if you're weakened and you get hit by it, you probably wouldn't even have time to Erase before you drop.
They've got another single-target, big damage attack, but I can't recall the name of it. Anyone know?