Lets take a look at cards where toughness matters. These cards work as your sneaky defenders, often turning a passive defense into a deadly attack
Guac & Marshmallow Pizza doesn't seem to give much to the combo versions, but the untap might spawn a different variant that could have some mana dorks - or enables a new combo altogether
Dominaria, Innistrad and M12 all provide solid cards that can fit in most decks, as long as you disregard the cards that depend too much on synergies (UR wizards,Burning Vengeance,Tribal cards from Lorwyn, etc.)
Geralf, the Fleshwright makes for an interesting storm commander
Although this Song is pretty pricey, it can make a huge difference to boost your Ink resources in mid/late game
In any case, this deck seeks to ramp up and hit its land drops using Sylvan Caryatid, Courser of Kruphix, and newcomer Atarka's Command