This build of Grixis Pyro Delver has put me into the top 4 of 20 man competitive tournaments. I top 16'd a 60 man PPTQ, losing out of top 8 by tie breakers.
This deck is a tempo/control deck. It follows 1 of 2 game plans to knock the opponent out of the game, with neither being particularly favored over the other except in certain matchups.
Strategy 1, Stick an early Delver or an early Tasigur and protect it while blasting away opponent's blockers or tempoing them out and forcing your opponent to play out of curve to resolve spells or to clog their hand while you gain incremental mana advantage.
Strategy 2, Resolve a young pyromancer and start slinging spells and tempoing your opponent out. Generally, it is a good idea to resolve a t3 pyromancer with a bolt or spell snare held up. Young Pyromancer is your primary game plan against Grixis Death's Shadow and running a full playset ensures you're going to be able to out value them. Stubborn Denial becomes fairly irrelevant since Pyromancer gives you a token on cast of spells, not resolutions. Pyromancer is why you see this deck playing Remands and Shadow of Doubt main deck. This plan focuses on winning through card advantage as opposed to mana efficiency.
That's not to say that these strategies are mutually exclusive; in fact, they support each other quite well. As pyromancer gains more value heading into turns 4-6, Delver usually resolves and flips and continues the pressure as you're left with plethora of 1/1's and a flying 3/2.
It's not Grixis Death's Shadow. It doesn't want to be. It focuses on mana efficiency, refusing to sacrifice life points for additional velocity. This deck has much better mid game than GDS and its redundancy renders the discard running rampant in my meta also fairly irrelevant.
The sheer amount of MD removal, counters, and cantripping this deck runs means that the sideboard is fairly free to run powerful and narrow cards like Blood Moon, Ceremonious Rejection, Painful Truths, and Crypt Incursion (sweet tech for the burn, dredge, and living end deck)
