Via Blogatog Mark Rosewater: I think well see more of both. While this doesnt immediately seem like an endorsement of future Un-set types in mainline sets, reading between the lines does support such a take
Once your graveyard is stocked with seven or more cards, each attack exiles one at random, and you get the chance to play it that turn
The big concern with expensive commanders is always that your opponents will have ample time to find their interaction and snipe that first cast, especially with counter-magic
The flexibility to fix draws early, buffer your life total for the backswing, or blink another creature you own is really something
A 4-mana with Toxic 2 is fine, and adding more Toxic to your Toxic creatures can definitely cause problems
It was he who placed the Queen as an obstacle for our Weatherlight heroes quest to reclaim The Legacy, and as a result, Sliver Queen was a pawn in the machinations of a dude named Vuel