8th Ed. Mythic Artifact for a skink priest

Is it for Storm of Magic where Presence, Equilibrium, and Dominance matter or is it a mythic artifact for regular games? A lot of items are dependent on P, E, or D. If you can't get those states that lowers the choices by a lot. Without a regular arcane fulcrums it rules out the Wyssans Weighted Dice, Arabyan Puzzlebox, Living Deadwood Staff, Fozzrik's Floating Fortress, the Dawnstar Sword and the Black Book of Ibn Naggazar.

If you are riding the EOTG Stegadon that pretty much rules out Windcatcher Prism since it carries over to the unit and the priest won't be leading a unit. Likewise the Stegadon rules out the Giantkin Helm. With no unit with expendable allies to sacrifice you can rule out the You probably don't want the Blade of Last Resort either since it's for expendable fighty characters. Stegadons can't occupy buildings so the Paranoth's Piquet Fence is ruled out.

That pretty much leaves the Dodechedron of Continental Drift (which requires a modular terrain board), Rockcharmer's Flute, and the Woodwaker's Wand. I'd recommend the Woodwaker's Wand, it lets you turn any forest into a badass monster for your side.

 

Probably not, the Woodwaker's Wand is hard to beat.

If you are good at Mathhammer, Wyssan's Weighted Dice might be good. If your battlefields are typically choked with forests the Living Deadwood Staff would be better.

If Monstrous Arcana Mythic artifacts are allowed, the White Sistrum would probably be best. As a baseline it gives the wielder lore master of Shadow and his mount poisonous attacks plus additional things for Presence, Equilibrium and Dominance.