The Sword Halls are an arena style instance with 3 bosses: Sorcerer (left door) - Summons fire. Keep moving to avoid or drop a Captain Banner. Morroval (right door) - Summons bats and heals (interrupts!). Olog Hai (middle door) - AOE dps, and does a huge aoe knockback (avoidable, stay in the blood stain left of the entrance). All three bosses have corruptions that give them +15% incoming damage (meaning you do more damage to them), that when removed, provide buffs to the group. The Sorcerer gives a heal, the morroval gives a power heal, and the olog hai gives a bonus to your damage mitigation. If you're at a tough part of the fight, it's best to removal the corruptions. If you're at an easy part, keep them on to speed up killing.
Easy Mode Guide
Easy mode is just that, easy. You fight useless adds (2 pulls before each boss, each with 3 mobs, they drop the quest items), and one boss at a time (Sorcerer -> Morroval -> Olog Hai).
REWARD - 3 Medallions of Dul Guldur and 3 Chests full of runes and relics
Hard Mode Guide
In Hard Mode (or Challenge Mode) you must defeat all 3 bosses at once (adds spawn after about 10 minutes, meaning you need to finish before then). The key to this is a good group combination. Healer, Tank, DPS is the best combo. The tank can tank two of the mobs (Olog Hai, and one other), as the DPS kills the remaining one (group make up dictates which you kill first). With a champ, guardian and minstrel, it was easier to kill the morroval first, so I could stop it from healing, and keep the bats of the mini. With champ, captain and minstrel killing the sorcerer first was easier since it's fire is the most annoying, and it has the lowest hp. It should be noted that the morroval MUST be interrupted, or kept on the opposite side of the room from the boss being dps'ed.
For those that really excel at their class having the Guard/Champ/Warden tanking all three mobs is very doable. Using the corruptions early on to help off-set the damage the tank will take helps tremendously.
REWARD - 4 Medallions of Dul Guldur (+3 from daily quest) and 1 Chest full of runes and relics
