so in Vanilla and SL we have Unstable Artifacts, Ember Isle introduced Twisted and PTW introduced Poison/Burning/Nightmare, Autumn/Fae Yule/Spring/Summer have their own Artifacts.

So lets talk Nightmare Tide and Ankhet, you are welcome to just put Unstable in more zones but why not go unique and add Nightmare Artifacts in PoW as an event with nightmare artifact thieves and a nightmare buff permanently applied during the ZE

for Ankhet what would be wrong with having ZEs for Celestial type Artifacts, perhaps a bonus for use of Opie use in the event wether to reduce his skill costs or a bonus award of some sort, and you love your thieves so lets add some Similacrum Artifact Thieves