My version of a pauper mono black devotion deck with Gary as the win con.
Disciple of Phenax is probably the second best creature in this deck. The cost is a little high but the no restriction discard can certainly change the game, and it's in the devotion theme.
Liliana's Specter can come out turn 1 with a Dark Ritual and mess up someone's opening hand. Turn 2 Duress into Dark Ritual into Liliana's Specter can put someone in top deck mode which is great to stall out until Gary hits the board.
Faceless Butcher has proven to be very helpful. He can snatch up annoying creatures from your opponents, or if you're desperate/close to winning, exile Gary, chump block or Grasp of Darkness Butcher, then Gary comes back into play relatively free. He's especially good at dealing with huge finishers like Ulamog's Crusher, even if it's only stalling out one turn.
Sangrophage is an auto-include in this deck, considering how easy it is to gain 6+ life with Gary. The early pressure from a 3/3 either draws out removal or just brings them down for Gary to finish them off. Well worth the life-loss.
The spells are pretty standard for mono black:
Sign in Blood so you can get to Gary as quickly as possible.
Grasp of Darkness for cheap removal.
Dark Ritual for explosive turns.
Duress to get rid of counter/removal spells, and Distress for unconditional discard.
This deck has been super fun to play and I think it's become more streamlined since I've started seriously testing it. The heavy discard theme really helps to stall things out and deal with potential threats.
