Like most trolls, these use Diamondhide... pretty potent Stoneskin x.x Couldn't dispel it...
Casts Tier 3 nukes, Bio 3, Dispel... Didn't see much else since I kept it Silenced most of time <_<;
Might be a good idea to use Dispel yourself at the start of fighting these coz they may have some buffs up from before being pulled (Shell Protect Bar- etc).