Lunthistle's Tale

He is in a cage at about 29.25, beside a pool of lava, on Firewatch Ridge in Searing Gorge. You'll more than likely run across him in his cage when you are after the Twilight necklaces.

Spoiler

TLDR; Zamael gives you a quest that can be completed anywhere for a one-time-only stamina boost.

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While questing in Searing Gorge, You'll find the ghost of questgiver Zamael Lunthistle (29.4, 26.4) trapped in a cage west of Thorium Point.

He starts 2 quests: Lunthistle's Tale and Prayer to Elune.

Lunthistle's Tale:
You talk to the guy a few times and BAM! Quest Complete. After that, he will give you the quest Prayer to Elune.

Spoiler

Lunthistle's Tale
"Praise Elune! It has been many years since I have had visitors."

-I wish to hear your tale.

"As a young night elf in Darkshore, I crossed paths with a group of unsavory individuals known as the Twilight's Hammer. A group of them befriended me and shamefully, I ended up eschewing my faith in Elune and embracing the vitriol of the Twilight's Hammer.
It was not until a vision came to me from Elune, that I woke up from the malaise that I had fallen into as a follower of the old gods.
In repentance, I began work on my prayer to Elune."

-Please continue, Zamael.

"Etched into a tablet of pure gold was the embodiment of my remorse, shame, and sorrow. Unfortunately, the Twilight's Hammer found the tablet and branded me a blasphemer. I was summarily executed, my prayer to Elune incomplete. I am now bound to this world as a spirit, unable to transcend to the Nether: held in this cage as a warning to all that would betray the faith of the Twilight's Hammer."

-Let me think about it, Zamael.
www.wowwiki.com/Zamael_Lunthistle
Please note: These words are a little bit dated, but I can't remember exactly what he says now and this is the best I could find.

Prayer to Elune: (quest map)
You have to find and read¹ the item Prayer to Elune. It used to be a mob drop, but now it is contained in Twilight's Hammer Crate (23.1, 35.5). The Crate is located just outside of Firewatch Ridge.
(1. The item is not actually readable. You just need it to complete the quest.)

This quest can be completed (once only) any time and in any place.
Completing the quest gives you Zamael's Prayer.
Note: According to NinjaLooterLoveU, this may not work if you already have a stronger 1-hr stamina boost. My advice would be to drop the stronger boost, complete this quest, then add the stronger boost back on top of this.
Note2: I have thanked NinjaLooterLoveU ("upvote") for the information, and I think you should too.

Lunthistle's Tale https://www.youtube.com/watch?v=4QXhf_KTcEw