In the House of the Red Crane

Objectives
Enter the basement of the Temple of the Red Crane and defeat the Sha of Despair.
 * slain

Description
"Broken are the bodies wherein hopeless hearts reside - the blight of despair strikes forth from inside."

This was the last piece of wisdom the imparted to me, just hours before the Sha outbreak. It makes sense now...

, when the Sha attacked, they broke forth from the temple's basement...

All of his teachings - the very Way of the Crane itself... it's all been preparation for facing the Sha of Despair.

The Red Crane has been expecting this conflict for centuries!

("Sha of Despair: Haunting the basement of the Temple of the Red Crane.")

Rewards
You will also receive:

Completion
You have vanquished the Sha of Despair. My order can handle the remaining cleanup from here.

It seems the time has finally come to face the consequences of Shaohao's actions.

This conflict has been a long time coming - the arrival of your people was merely a catalyst. Now, your help will be necessary if Pandaria is to survive.

Gains

 * 161000 XP
 * +250 reputation with August Celestials

Tips
Interrupting Gloom Whirl is vital, so always keep the Sha of Despair targeted. Killing the Echoes heals you, which is extremely helpful if you cannot heal yourself.

Despite Anduin's advice, there is no need to defeat the Echoes of Despair summoned by the Sha's Call of Despair attack. Despite re-casting the Call of Despair, the Sha does not appear to summon more Echoes unless some have been defeated. Once the Sha is defeated, all Echos are instantly dispersed. Ranged classes can therefore simply stay out of aggro range of the Echoes, and focus all their attacks on the Sha itself.