Decks that play an interactive midrange game have been gaining in popularity in the Modern format. They have no glaring weaknesses and present a tough matchup for Death’s Shadow.
Smallpox lets its player build tons of advantages into their deck, and decide when it’s most relevant in a game. It can be used for a small advantage early, or a large advantage later. Smallpox is a symmetrical effect for which you’re spending mana and a card, so breaking that symmetry is key.
Each player discards a card, but you can mitigate that if you have flashback spells or cards that come back from the graveyard (or can simply empty your hand). Each player sacrifices a creature, but you can make that less impactful by having creatures that come back, tokens, or just not having a creature in play. Each player sacrificing a land is the hardest to leverage, but Flagstones of Trokair makes sure that isn’t a cost, and you can construct your curve so that it isn’t heavily impacted by the land loss.
Lingering Souls has a similar effect, but it also presents a real clock. You don’t mind discarding Souls to flashback later, and the tokens will protect your life total and your many planeswalkers.
And this deck is completely packed with planeswalkers, which aren’t impacted by Smallpox while also being extremely strong against cards like Fatal Push. Gideon, Ally of Zendikar is capable of creating an army or ending the game on his own. With enough tokens from Gideon himself, other planeswalkers, Lingering Souls, or simply Bloodghasts, the emblem becomes a huge threat. Sorin, Solemn Visitor also creates an attack force while buffering your life total to make racing impossible in matchups where that’s relevant. The ultimate can be game winning in some of the midrange matchups you might face.
Liliana of the Veil is ridiculously strong in Modern, and that’s been the case for as long as she’s been around. The value of making an opponent sacrifice a creature and still having your 3-mana planeswalker in play is phenomenal, and simply ticking up to ultimate is unbeatable in some matchups. This combines nicely with Smallpox to make sure your opponents can’t keep any creatures in play or cards in their hand, and you have plenty of cards you don’t mind discarding (again, Bloodghast is insane here).
There’s the full playset of Thoughtseize and Inquisition of Kozilek, as is becoming the norm in many black decks in Modern. These cards are too efficient, and they completely mess up the opposing game plan. There’s no matchup where early discard isn’t effective, and this is the best way to make sure you always have interaction no matter what you face.
In order to maximize your Smallpox and Liliana edict effects, Fatal Push offers some instant-speed spot removal that can also deal with creaturelands. For an extra dose of Edicts with some token production, Oath of Liliana is quite strong in this deck.
With tons of great sideboard options in both black and white, as well as an abundance of fantastic interaction in the main deck, B/W Smallpox looks like a powerful shell for a deck looking to prey on all but the most aggressive of creature decks.