You Are Rakh'likh, Demon (Alliance)

Objectives
Speak with the Deathly Usher north of the Rise of the Defiler. Once atop the Rise, destroy Razelikh's body, then use the Stone Knife of Sealing to imprison his soul. Provided item: Stone Knife of Sealing
 * Razelikh's body destroyed
 * Razelikh's soul imprisoned

Description
Hero, listen well.

First, we must travel to the Deathly Usher, who waits at the northern foot of the Rise of the Defiler, to our northwest. The usher will take us to the top of the rise. Once there, you will help me defeat Razelikh, for I fear I am not strong enough to defeat him alone.

Most importantly, I need you to hold the stone knife, and do not use it until I tell you to. The knife will trap Razelikh's soul within its new, eternal prison.

If we succeed, speak with Grimeo, the draenei.

("Rakh'likh: Your knowledge of his true name shall prove to be his undoing.")

Rewards
You will also receive:

Progress
You again? Has Kasim found more work for me?

Completion
Loramus, resurrected!? And then he trapped the demon inside his own body... by the Light...

I see. So this was Kasim's plan all along. I suspected correctly, but I suppose I refused to believe it.

Ah, one last thing! Kasim left one more instruction for me within his rune. I did not understand it at first, but given the events that have taken place today, it now makes much more sense:

He asked me to let you choose from one of these.