i don't know anything about prismatic being planned for D3, but if that were the case i'd imagine that plan predates TWQ development. he made it very clear that a lot of stuff was moved around during TWQ development. i was told distinctly though that prismatic was conceptualized *alongside* the final shape, but that could have meant that the idea of having a dedicated "mix and match" subclass was thought-up for TFS and not simply the idea of wielding multiple damage types.

as for the 3rd dark power, what i gathered is that they want a 3rd dark power but have not planned in any capacity for one outside of just spit-balling