Pets with the appropriate AA do not get hit by his mighty swing ability; 3 lvl 100s healing merc on reactive could barely keep up a decently geared ( VoA T4 raid gear) SK with 8000ish AA but a simple beastlord pet ( with group gear ) never dropped below 80% with only a single healing merc on balanced.
something is wrong...
Also, out of 5 kill he never dropped a dreadmote, and never dropped fear stained / fear touched items... might just be bad luck however.
An easy fight for a named. The DOT was able to kill my level 100 warrior merc, but not an necro or mage pet (air). Be sure to clear the area. Several gorals roam close by.