The final showdown: Destroy Illidan Stormrage, and free Outland from his iron grip!
Seer Kanai wants you to defeat Illidan inside the Black Temple.
The Medallion is required to enter the Black Temple; this quest allows the bearer to upgrade it so that it can teleport the bearer to the Black Temple's gates from anywhere in the worlds (much like Atiesh, Greatstaff of the Guardian is used to teleport wielders - and their parties - to Karazhan).
With Illidan's lieutenants defeated, Akama will be able to force open the doors to Illidan's sanctum. Be ready to bring your force inside as soon as Akama does.
We still do not know what has become of Maiev, but we must make our move without her.
I hope your force is up to the task. Illidan will not be pleased to see Akama.
It is as it was foretold, <name>. One by one, Illidan's lieutenants have fallen... and now the Betrayer himself has met his demise!
Know this, <name>: every decision Akama made and every moment of his life since Illidan arrived, Akama planned for this moment. Illidan is finally dead and our people... are free!