It works outside Cyrodiil.

Syiccal wrote: »

Is this the same for all mythic?

Yes, no mythic will work in Cyrodiil until the next update as far as we know.

*** ring of the wild hunt works just fine

If the bonus is anything other than a flat base stat bonus, it won't work. Calling it "disabling proc sets" definitely creates confusion, as it's reach is much greater.