Daio the Decrepit (quest)

Objectives
Fly to the Tainted Scar in the Blasted Lands and get information from Daio the Decrepit.
 * (Optional) Take the Portal to Karazhan
 * Fly to the Tainted Scar and find Daio
 * Speak with Daio
 * Survive Daio's Challenge
 * Get the Demon Stone
 * Blasted Lands Scroll (provided)

Description
That text lists someone named Daio as being instrumental to the demonic ritual. They can't possibly mean Daio the Decrepit!

I never knew he was Kirin Tor. I only know him as an elderly warlock who trains young recruits in the infernal arts. This would certainly explain his change of occupation.

He most likely holds key information for this to work. Though retired, I believe he is still out in the Tainted Scar in the Blasted Lands. You should seek him out.

Rewards
You will receive:
 * 15,050 XP
 * 15,050 XP

Progress
Well, what did Daio have to say?

Completion
Our order suffered a great loss that day. It is a shame we chose to hide it instead of study it.

You have another critical element to the ritual, and we are one step closer.