Would b/w builds want to run Dryad Militant for the passive exiling of instants and sorceries? Also, if we were to process an instant or sorcery with her on the battlefield, would the processed card then be exiled again, and would the processor effect still happen?
I wouldn't doubt that rest of the cycle could be completed in Shadows over Innistrad, like how WotC completed the enemy pairings of the Glacial Fortress cycle with the original Innistrad.
Scions and Spawn do that.
Phyrexian Snowcrusher seems like it would be a good addition.