You can tell by mousing over the buff/debuff icons directly below his name in the target window. What do those say before and after you enter combat?
Crogyn has the correct buffpackage in solo, called Metallic Bond. You know it's a solo buffpackage as it will not have a listing for Resolve, as solo mobs don't use Resolve.
Okay. Well he does say for 3+ people. And had no obvious strat. Someone just told me how to beat him. Over 20 deaths lol. Great job on these zones by the way! Fantastic. Edit: Did you guys put Plumes in this loot table anywhere?
You have to examine his det to see what to do. If you examine his det when he gets it, it tells you to dispel or HO to remove it