Here are the altercations that I think will improve this deck:
4
Rancor - Fast buff that stays with you, plus the trample, in fact, I believe this card is a must main deck, I just didn't have it when I built this deck
2
Giant Growth - Fast buff
2
Titanic Growth - Buff
1
Increasing Savagery - Steriods!
Also, feel free to substitute
Evolving Wilds for dual lands and a complete set of
Verdant Catacombs if you have to money. Also,
Devour Flesh can help with hate if you want.
To be honest, anything else other than fast creature buffs will decrease the speed or alter the deck format in which it was designed for: Fast damage. The main point is that when dealing with poison counters, your opponent is pretty much playing with only half of their life (10 LP), so you need to get the damage across fast; a caveat is that infect creatures are weaker; compared to their counterparts that deal normal damage, hence the emphasis on buffs. Also, the numerous hate cards provided by black to eliminate blockers. The format is really quite
simple, but very effective.
Inkmoth Nexus - Infect Creature that is also land, similar to the Standard Mutavaults. A key card in this deck.
Bojuka Bog - Simply playing against a graveyard
Skithiryx, the Blight Dragon - Finisher
Putrefax - Finisher, the Haste + Trample combo is the point in this, since the creature isn't going to last anyway.
Hand of the Praetors - Boost any infect creature out there, plus adding a poison counter to your opponent whenever you cast a creature with infect (good thing all of your creatures have infect!)
Flesh-Eater Imp -
Simple flyer
Tangle Angler - This card doesn't seem very effective at first, but it can easily handle all of the blockers in order to get your damage through in one swoop, and it plays a vital role!
Phyrexian Crusader - An attacker, but also his protection from White and Red is a bonus when dealing with several decks, a metagaming card!
Plague Stinger - Fast flyer,
simple and sweet.
Birds of Paradise - A multipurpose card, this card just doesn't provide the mana boost or cheap blocker, but its real purpose is used for
Praetor's Grasp; allowing you to pay for any colored mana that the card may require.
Mutagenic Growth - Fast buff, life doesn't matter with this deck, it is a race; remember: Poison counters, your opponent is already at half health!
Giant Growth - A quick buff, to be honest, more could be added, but the deck works fine.
Virulent Swipe - A buff; actually, a double buff! (Or a quick blocker - perhaps on a Bird?!)
Virulent Wound - Hate plus poison!
Doom Blade - Hate
Savage Surge - A buff or untap for blocker after an attack - could be swapped for
Titanic growth/
Giant growthDismember - Best hate! Especially for those indestructible creatures.
Praetor's Grasp - Metagame card! Or if you want to just look through someones deck, oh, and your Birds! Guess you could play them too!
Diabolic Tutor - Get what you need to finish the game
Caress of Phyrexia - If your creatures can't finish, then this is your victory.
//Sideboard
Go for the Throat - Hate
Geth's Verdict - More Hate
Doom Blade - Additional Hate
Naturalize - Artifact hate
Relic Putrescence - If someone is artifact dependent, this should make them weary about tapping it (talking to you Myr!)
Praetor's Grasp - Additional deck search (of opponent's!)
Dismember - Hate
Glistening Oil - A sneaky trick, such as taking an opponent's creature (
Praetor's Grasp), then giving them Infect, or if your life is low, giving yourself infect damage instead may prolong your life; possibly just the amount you need, also a weenie hate.
Caress of Phyrexia - Additional victory source.