Grixis is one of the more powerful color combinations in Modern. Death’s Shadow decks have mostly adopted Grixis for the powerful card draw, removal, and creature suite that synergizes with the graveyard. Grixis Control has been championed by Corey Burkhart as well. Taking the best of both of these decks and adding a finisher that remains popular in Vintage and Legacy could be the best build of them all.
Young Pyromancer is a great early threat that brings inherent card advantage, letting you cash in your 1-mana spells for additional creatures. Attaching that to something as cheap as Young Pyromancer is a fantastic threat. With a bunch of 1-mana card draw spells, discard spells, and removal spells, flooding the board with Elemental tokens is a breeze for this deck.
With so many cheap spells, Snapcaster Mage finds yet another home. As one of the best spells in Modern, Snapcaster is a reasonable threat, a blocker, and an absolute powerhouse when it comes to getting ahead on cards, cashing in a 1-mana removal or card draw spell a second time.
With so many cheap spells, the delve creatures are formidable threats. Removal spells like Fatal Push are going to be able to find value against your cheap Pyromancers and Snapcasters, but being forced to leave in those cheap removal spells may leave your opponents susceptible to your bigger monsters. Tasigur, the Golden Fang and Gurmag Angler can be cast as early as turn 2 for a single mana investment, and having a creature this large for that cheap creates an impossible board state to handle.
As for card drawing, there’s nothing really better than Thought Scour. While it won’t give you any particular card selection to your hand, you do get a plethora of extra options for your Snapcasters. Putting three cards into the graveyard is great for getting delve online, and just having more 1-mana instants makes Pyromancer a better threat. Since you can’t play more than 4 Thought Scours and you want more cheap instants, the playset of Opts also makes the cut.
Discard spells have matchups and turns where they’re incredible, but they can be terrible topdecks in the late game and there are matchups where you really have no interest in them. You’re playing fewer copies of both Thoughtseize and Inquisition of Kozilek for those reasons, but having a handful of discard spells can protect your Pyromancers, disrupt a combo, and also make some tokens.
Grixis means that you have access to both black and red removal spells. That means creatures aren’t long for this world. The full playset of Fatal Pushes take care of many of the earlier threats, and a playset of Kolaghan’s Commands is incredible for card advantage and taking out artifact-centric decks. The combination of Kolaghan’s Command with Snapcaster to kill something, bring back Snapcaster, and Command again creates what my mental math is telling me is a 100-for-1. A couple Lightning Bolts and Terminates round out your suite of removal and give you some additional options to kill bigger creatures and burn your opponent out, both of which are extra important with Snapcaster Mages to rebuy the value.
With a deck that has creatures that cost 1 and 2, discard spells that cost 1, and a bunch of instants, countermagic is a perfect fit. If you leave up mana, you can cast a card draw spell or removal spell even if they don’t play into your counters. This lets you play a few copies of Mana Leak for extra interaction, and a Remand for a nice tempo play.
Getting to play efficient threats, lots of versatile removal, a low land count to avoid flood, and interaction in both discard and counters is a great recipe for success in the Modern format!