Cathedral of Eternal Night: Altar of the Aegis

Objectives
Defeat Lord Mephistroth and place the Aegis of Aggramar upon the Altar of Eternal Night.
 * Defeat Mephistroth

Description
Champion, we are ready to assault the Tomb of Sargeras.

I studied the writings of Aegwynn, the Guardian who defeated the Dark Titan's avatar. She said that if her wards were compromised, a failsafe could be triggered by placing the Aegis of Aggramar upon an altar in the Cathedral of Eternal Night.

You are the hero who acquired the Pillars of Creation,. Gather your allies and enter the Cathedral. Be warned: Mephistroth will use all his power to stop you from placing the Aegis. You must prevail!

Rewards

 * +1,000 reputation with Armies of Legionfall

Progress
There is little time. Mephistroth must be defeated, and the Cathedral of Eternal Night secured.

Completion
Mephistroth is dead and the Cathedral is secured, but the lower reaches of the Tomb remain in the hands of the Legion.

This is not the outcome we wanted, but this fight is far from over,.

Do not relent. Give the Legion no quarter, no place to hide. When we are ready, we will take the Tomb and drive them from Azeroth!