Nightbane - summoning an undead dragon

Once again the brave forces of the Violet Eye ventured forth into Karazhan, this time to summon the undead remains of Arcanagos, now named Nightbane, in an attempt to recover a Faint Arcane Essence of Medivh himself. Well, those of us with the quest did.

Typically Kam was there as Elemental DPS, so some standing at the back throwing Lightning Bolts was the order of the day. Things I discovered were:

• Totems are immune to charred earth effect Nightbane puts on the ground. This is very handy because generally I had to run around to get out of charred earth, if the totems were affected they would be burnt within about a second.
  
• One Tremor Totem per group is very good here to stop those fears dead.
  
• This is a long fight, 9 minutes, so Lightning Bolt spam is the most mana efficient "rotation" to use if mana is an issue. Can you rotate between the same spell? Probably not...
  

The fight ended with Nightbane dead and those mysterious Violet Eye types with more Medivh residue, whatever they are doing with it in that purple bubble of theirs. Growing a new Guardian of Tirisfal is my bet.