Grand Commander Ruusk is a level 72 elite Eclipsion blood elf located at Eclipse Point in Shadowmoon Valley. He is very tall.
He is involved in the quest  What Illidan Wants, Illidan Gets.... While he is normally hostile and can be killed, there is no quest to do so.
Conversation with Ruusk
Disguised as an Illidari blood elf, the player has the following conversation with the Grand Commander:
- Who dares interrupt the Grand Commander?
I bring word from Lord Illidan.
- I'm listening.
The cipher fragment is to be moved. Have it delivered to Zuluhed.
- Oh? Of course you have papers documenting this request.
Perhaps you did not hear me, Ruusk. I am giving you an order from Illidan himself!
- Listen to me, peon. We have a process for the delivery and safekeeping of the cipher fragment. The envoy delivers the missive, which is sealed by Lord Illidan. No missive, no transfer.
- <The Illidari Slayer moves in behind you with his axe at the ready.>
Very well. I will return to the Black Temple and notify Lord Illidan of your unwillingness to carry out his wishes. I suggest you make arrangements with your subordinates and let them know that you will soon be leaving this world.
- <Ruusk swallows hard.>
- I... what do you mean?
Do I need to go into all the gory details? I think we are both well aware of what Lord Illidan does with those that would oppose his word. Now, I must be going! Farewell, Ruusk! Forever...
- Wait. Where are you going? You needed a transfer, correct? Let's just get it done and over with, ok? Zuluhed at Dragonmaw? It will be done. Please let Lord Illidan know that his orders were carried out with the full cooperation of the Eclipsion.
- I will dispatch Ruul the Darkener to personally deliver the fragment!
- You heard me right - Ruul...
Ah, good of you to come around, Ruusk. Thank you and farewell.