The Drolvarg Captain from Lceanium is tough, hits hard and has lots of HP but nothing super dangerous.
Area effect popped the lowest (101) Merc, but a 105 SHM, 104 SHD & 101 NEC w 3 Healer Mercs killed him in under 5 minutes.
(3 Players not 3 Box)
Be prepared to chain heal tank even with the mercs.