There's precious little on the builders, or at least what is known, and on the seven fallen empires of the Eastern Woes, not even a good sense for how long ago that was.  While the concept itself still interests me, I'm not sure I'm a good fit for lore the way it has been presented, nor for a game with multiple pieces in different places.

I'm wondering what caused the decline of the world in general, since it certainly appears to have done so.

And my question about Manifests was more...hm.  Can they cast any spell related to their element (at least potentially), or only the ones that an artifact in their possession is capable of casting?  So is it them casting the spell and the artifact just negating the cost, or the artifact casting the spell and the manifest needing it in order to do so.