Originally Posted by
Vandalize
I've found this deck to be really fun to play with, as I saw a lot of potential in Young Pyromancer. But this deck has one MAJOR issue. As a tempo deck (and in the Legacy format), this deck tends to empty its hand in the first few turns of the game, leaving us to topdeck mode. As a pseudo-combo, Young Pyromancer requires you to play lots of spells, and if you're in topdeck mode, this is just not enough. Making one 1/1 token per turn after a Pernicious Deed or Terminus isn't enough.
The only advantage I see in Grixis over RUG Delver is the discard options, as Thoughtseize and Cabal Therapy are really strong options. But lacking a resilient threat (Goose) and a thug (Goyf) really hurts this deck if your early disruption isn't matched with the right clock.