Custodian Dieworth

Custodian Dieworth is a level 68 quest giver located outside the Violet Tower in the contested territory of Netherstorm. You must complete all the quests from Ravandwyr before any of Dieworth's quests are available.

He starts the following quests:
 * (Group)
 * (Group)
 * (Group)
 * (Group)
 * (Group)
 * (Group)
 * (Group)
 * (Group)
 * (Group)

See List of Netherstorm NPCs.

Quote
Kirin'var surived 20 long years and countless orc assaults, but it could not withstand the forces of Kael'thas. A man who once called himself a member of the Kirin Tor murdered all of us, save one.

Archmage Vargoth survived the attack, so Kael'thas imprisoned him within the Violet Tower, warding it with magic that forbids passage of any of the Kirin Tor.