Breath of the Undying Serpent - Hidden Mistwalker artifact skin

[Deleted]

Has anyone any information on this? So far I only found this:

Breath of the Undying Serpent, which unlocks the Breath of the Undying Serpent hidden appearance for the Mistweaver Artifact weapon ( Sheilun, Staff of the Mists), is dropped from the Dragons of Nightmare encounter in The Emerald Nightmare Legion raid instance.
This is an encounter where you face off against Ysondre and the nightmares of her former cohorts, (NPC #102683), Lethon and Taerar.

http://www.wowhead.com/item=139562/b...rpent#comments

But in the Rogue section, the Outlaws are looking for their Thunderfury appearance like crazy and say the GM's told them all hidden skins are available now. So our's must be too right? We know the WW one comes from the Withered Army scenario and the BrM one from the level 2 brewhouse keg.

Any clue on the Mistwalker one?

[Staargasm]

It does say, right there in the text you've copied, that it drops from a raid boss in The Emerald Nightmare, just because some skins are available right away, it doesn't mean that every skin is. You'll have to wait for the raid release.

[Powell]

I'm pretty sure they mean that all hidden skins are currently in-game, that doesn't necessarily mean they're accessible at this time