I really like your build. I play a Savra deck too. Abyssal Persecutor is brilliant in it. haha. Cards for recommendation:
Momentous fall: Nothing like drawing ten then gaining ten off of Doomgape AND making your opponents all sacrifice with Savra in play
Corpse Dance: Reusable reanimation effect. You can sacrifice the creatures to put them into your graveyard so they do not get removed from the game. (Works REALLY well with Symbiotic Wurm and some M 2011 cards (Don't want to spoil any))
Perilous Forrays: It just gets ridiculous with bloodghast. Double the amount of lands you have in play every turn.
Altar of Dementia: Can be really good with universal graveyard reanimation. Dump your opponents best creatures into the graveyard to reanimate then yourself. but it can be a double edged sword.
Mind Slash: Targeted discard can be really strong. Get rid of their sweeper so you can feel safer committing.
Creakwood Liege: A great token producer that buffs your creatures as well as giving you multicolored tokens (which savra just loves)
I would also consider some doomgapesque cards like archdemon of unx and xathrid demon. They're not bad.
Attrition is not terrific. Your opponent can just sacrifice the creature you target to destroy so you don't actually get the two for one unless your opponent is not paying attention. It's still a good sac outlet but there are some better ones like even golgari rotwurm isn't bad.
These are just suggestions from my deck but i don't play stax so i'm not sure how it plays. Otherwise i really like your deck.
Momentous fall: Nothing like drawing ten then gaining ten off of Doomgape AND making your opponents all sacrifice with Savra in play
Corpse Dance: Reusable reanimation effect. You can sacrifice the creatures to put them into your graveyard so they do not get removed from the game. (Works REALLY well with Symbiotic Wurm and some M 2011 cards (Don't want to spoil any))
Perilous Forrays: It just gets ridiculous with bloodghast. Double the amount of lands you have in play every turn.
Altar of Dementia: Can be really good with universal graveyard reanimation. Dump your opponents best creatures into the graveyard to reanimate then yourself. but it can be a double edged sword.
Mind Slash: Targeted discard can be really strong. Get rid of their sweeper so you can feel safer committing.
Creakwood Liege: A great token producer that buffs your creatures as well as giving you multicolored tokens (which savra just loves)
I would also consider some doomgapesque cards like archdemon of unx and xathrid demon. They're not bad.
Attrition is not terrific. Your opponent can just sacrifice the creature you target to destroy so you don't actually get the two for one unless your opponent is not paying attention. It's still a good sac outlet but there are some better ones like even golgari rotwurm isn't bad.
These are just suggestions from my deck but i don't play stax so i'm not sure how it plays. Otherwise i really like your deck.