The Summoning of Droga  

Preface: Every goblin in this mission except for Droga himself uses the Goblin Whirl spell. Hope you like spin-stuns! Also, every goblin is rooted in place.

The mission area is restricted to the NW corner of the zone, around the blood pool. Once anybody steps into the main room and gets on aggro, everybody is pushed into the room and the event timer starts. The High Priest casts Blood Fall (a 120K small AE around the person targeted) every 15 seconds once the event starts, whether he is on aggro or not, so spread out a little while fighting.

High Priest of Droga shouts, 'The ceremony must not be interrupted! Droga shall rise and lead our armies to victory!'

There are six priests of Droga around the blood pool, with small aggro and assist radius. Each casts Blood Sip (a 70K DD) 10 seconds after entering combat, then every 15 seconds until dead. You kill the priests so that you don't have to deal with them later while fighting Droga.

There are two tunnels from the blood pool area leading up to access the High Priest of Droga, on the East and West sides of the room. There are warriors of Droga on both paths, but the East path has fewer warriors to defeat if you are fighting your way up. You can choose to run past the warriors and head straight to the High Priest, since the warriors are rooted in place.

The High Priest is a belly caster, so you cannot kill him from the ground floor. He continues to cast Blood Fall while you fight him. There is a six minute timer from event start to prevent the High Priest from completing his ritual. You must kill the High Priest, regardless of whether he finishes his ritual. There is an emote for failing to kill him in time. Once the High Priest is dead, The Incarnate Droga spawns in the blood pool below you.

High Priest of Droga shouts, 'The ceremony... Droga shall wither without my guidance... but may he yet crush... our enemies...'
The ritual is disrupted by the high priest's death, and the incarnation of Droga emerges deformed!

The Incarnate Droga casts Axe Whirl (~28K PBAE) every 10 seconds and Blood Splash (~98K PBAE) every 40 seconds. He has a warning emote ("The Incarnate Droga craves Yourname's blood.") before casting Blood Bath (a 65K small AE that flings you to Droga) on the targeted person. At low health (<30%?) he may start spawning a bone golem that self-destructs if not killed (Bone Explosion: 105K PBAE). A good burn on Droga means bypassing the Blood Bath and bone golem mechanics.

The Incarnate Droga collapses in defeat, releasing the spirit of Droga and foiling the high priest's plans!
You disrupted the ritual and removed Droga's spirit from the physical world.

The reward chest can drop any of the visible armor or Deep Mine Bulwark, and has a chance to also drop an Extra Planar Potential Shard.

There are three achievements for this mission.
Keep it Short: Win without allowing the high priest's ceremony to last more than six minutes.
Safety: Win without allowing any of your party to be killed.
No Bones About It: Win without allowing any of the bone golems to self destruct.

Be sure to engage Incarnation as soon as he goes active, failure to do so will reset the mission! unlike the raid, the leftover trash mobs around the outer perimeter will not rush the boss once he goes active.