Warmother Captive

[npc=134625] rare is located in Vol'dun Thundering Terrace on Zandalar isle.
He is near the south part of the bridge to the Slithering Gulch.
Find the bridge east of Horde Vorvik's Sanctrum windrider
You can see it on the map under the Temple of Sethraliss entrance

For TomTom users
/way Vol'dun 50.70 30.77 Warmother Captive

Warmother Captive location video: https://www.youtube.com/watch?v=MGYe-dcAzrU

Main post about Vol'dun rares is here: Adventurer of Vol'dun

Enter the Slithering Gulch and go up at 52.6,34.0
Turn right, cross the bridge and then left.

For Alliance: go to the Vulture's Nest flight point*

• Sight the cloth draped bridge leading up to the Temple of Seth'raliss (& dungeon).
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• Turn left when you reach the top of the high steps and head to the quest area.

*To open the Vulture's Nest flight point, reach Revered with the 7th Legion and buy the follower quest [item=163041] from [npc=135446] in Borealis. (She stands on a wooden platform near the stationary ship.) Watch for the follower quest. When that's done, you'll receive a couple of quests that will send you to Vol'dun to officially open the flight point.

See Mypciscraze's description of the Vulture's Nest quest series. There's a video and a list of additional Zandalar flight points you can access by purchasing follower quests from [npc=135446].