Harlow the Blackguard (click for map image) has a chance to spawn after the fourth step is completed in the Ethernere heroic adventure "A Helping Hand".
Harlow the Blackguard mem blurs himself and AE rampages.
Group was: 88 bst and clr merc 89 enc and clr merc 90 wiz and war merc
Harlow was red to all. Engaged at spawn with bst pet (EM XIII) using fellgrip jaws to slow, friendly, and runes. Tank merc engaged and ... was dead in 1 round (fully AFK buffed). Wiz was on silent casting but got caught off guard by blur and died about 90% mob health. Pet tanked and dps'd the mob till dead with 3 healers and enc keeping mob debuffed. Long fight. No mana issues but a couple puckers from some heavy bursts.
100 Shammy, 100 necro bazaar geared, necro pet EM14 tanked, 2 T5 healers, slow landed with no issues, both healer were at 80% at the end of the fight. Pet was never below 60% during fight. Fought him at the spawn point was simple.