Found in Deepholm, western-ish side of the Temple of Earth.   Item level of 272 required.

Corborus

• Crystal Barrage - Deals 2060 damage per 0.5 seconds to all enemies within 5 yards of the target location
• Dampening Wave - Deals 2575 shadow damage to all enemies within 60 yards, and absorb 400 healing, stacks to 20.   Dispels removes entire stack.

Notes:

• Phase 1 - Tank and spank, avoid crystals
• Phase 2 - Burrows under the ground, pops up where players stand, so keep moving
• Minor adds spawn around crystals to kill
• Repeat til dead.

Slabhide

• Sand Blast - 25K Nature damage 15 yard frontal attack
• Eruption - Deals 10K fire damage to all enemies within 5 yards, forms Lava Pool which deals 5K fire damage per second to all enemies within 5 yards, lasts 10 seconds.

Notes:

• Frontal damage, don't stand in fire
• Occasionally flies up a bit and makes chunks of the ceiling fall, avoid those
• Heroic:  Upon landing casts Crystal Blast big AoE but line of sightable with those rocks that just fell

Ozruk

• Ground Slam - Deals 89887 damage to all enemies within 8 yards of impact location, 3 second cast, targets tank
• Spike Shield - Spikes erupt from his body causing any melee attacks on him causes the attacker to bleed for 500 damage every 3 seconds, stacks to 20, lasts 10 seconds
• Elementium Bulwark - 20% chance to reflect spells for 10 seconds
• Spike Barrage - Launches spikes dealing 30K damage to all enemies within 15 yards, not mitigated by armor
• Enrage - Increases damage done by 50%

Notes:

• Does a tank knockback too, so tank against wall
• Avoid ground slam
• Don't kill yourselves

Heroic:

• Ground Slam is 500K lethal, avoid at all costs
• Gains a Paralyze + Shatter combo
• The Elementium Bulwark DoT will remove the Paralyze
• The Shatter will do 160K everyone within 15 yards
• Ideally, DoT breaks paralyze, run out asap

High Priestess Azil

• Curse of Blood - Increases target's physical damage taken by 1000 for 15 seconds
• Energy Shield -  Deals 15K arcane damage within 5 yards knocking them back, also gives her a shield reducing damage taken by 75% and the ability to fly
• Force Grip - Grabs a player and lifts them into the air, then slams them into the ground for 20K damage, repeatedly, not mitagated by armor, lasts 5 seconds
• Seismic Shard - Rips a chunk of earth from the ground and hurls it towards a player doing 34999 damage to enemies within 5 yards of impact location
• Summon Gravity Well -  A void zone that continuously pulls you to the center, where the closer to the center you are the more damage it does, lasts 20 seconds.

Notes:

• Can fly anytime, up to ranged dps whatever they can
• Randomly packs of 3 adds spawn, nothing but fodder to kill
• On the ground, Tank will be mainly Force Grip, players can interrupt it
• Avoid void zones
• Avoid rocks being thrown at you
• Heroic:  More adds more lethal, can use the Gravity Wells on them too to help you.