Winning through poison has some real advantages when compared to the standard 'get your opponents life to zero' approach.
- You only need to do 10 points damage to a player rather than 20.
- Damage done to opponents creatures by your poison creatures is permanent. i.e) rather than dealing normal damage that is wiped at the end of the turn, poisonous creatures deal damage to other creatures in the form of -1/-1 counters that persist past the end of the turn.
- There is still very little poison removal cards in Magic, and because of the rarity of Poison decks most players will not have any in their decks or sideboard.
Up until recently winning the game via the poison route was never really an option due to the distinct lack of available poison cards. With the arrival of the Scars of Mirrodin block (Scars of Mirrodin, Mirrodin Besieged, & New Phyrexia), that however all changed. Creatures with poison were defined as having an ability called 'infect' and for the first time the game focussed in on this method of winning. These sets were choc-full of poisonous creatures, and spells that made poison focusing decks have a real chance. Creatures such as the Phyrexian Crusader, Blighted Agent, and Ichorclaw Myr are great as entry level poisonous creatures with heavyweights such as the Blightsteel Colossus, Phyrexian Juggernaut, and Phyrexian Vatmother to finish someone off.
Another effect that what introduced to the game in the 'Scars of Mirrodin' block that has a strong synergy with poison decks is that of 'proliferate'. The 'proliferate' effect states that a player may choose any number of creatures and players with counters on them and add one additional counter of the same type. This obviously works well with poison counters on players and -1/-1 counters on creatures.
Below is a deck that specialises in poison and proliferation that I have used and has proven to be rather successful:
4 Ichorclaw Myr
3 Plague Myr
4 Blighted Agent
2 Hand of the Praetors
1 Tezzeret, Agent of Bolas
4 Drowned Catacomb
4 Inkmoth Nexus
4 Buried Ruin
2 Bladed Pinions
2 Livewire Lash
2 Throne of Geth
4 Corrupted Resolve
3 Grim Affliction
2 Mana Leak
2 Contagion Clasp
3 Virulent Wound
2 Tezzeret's Gambit
The key idea behind this deck is to get your opponent poisoned early, and then to continue to tick away at their poison count with various proliferate affects. Being a blue/black deck it also has strong control elements and as part of its strategy to prevent the opponent from becoming too powerful.
Inkmoth Nexus is essential as it is a turn two flying attacker with infect, the Blighted Agent is also great as it can't be blocked, and finally the Ichorclaw Myr is also a creature that your opponent will more often than not let through so it does not get its +2/+2 bonus when blocked.
The other creatures are secondary yet all play an important function. The Plague Myr ramps up the mana base while also having infect. The Thrummingbird provides a potential repeating 'proliferate' effect with every successful attack on a player. Finally the Hand of the Praetors, another infect creature makes your existing infect creatures bigger and provides another mechanism to give your opponent a poison counter every time you cast another creature with the 'infect' ability.
All of the spells and artifacts in the deck focus around two area's of game-play: Controlling the opponent or providing another mechanism to proliferate out additional poison counters. Traditional counter magic comes in the form of Mana Leak and Corrupted Resolve. Corrupted Resolve does require that the opponent has at least one poison counter, however you can expect that that will be the case from fairly early in the game.
Creature control comes in the form of Virulent Wound, Grim Affliction, and Contagion Clasp. All of these cards have the ability to potentially give your opponent a poison counter or to proliferate. Virulent Wound and Grim Affliction primarily deal with small creatures, but are there to maximise the poison/proliferation affects. Against decks where you face more powerful threats they should be sideboarded out in favour of more effective creature killers such as Doom Blade or Dismember.
The deck also includes two equipment spells, Livewire Lash, and Bladed Pinions, both of which work well in an infect based deck. The Livewire Lash is great as it inflates your infect based creature, but also states that if the equiped creature is targeted by a spell that the creature deals two damage to a creature or player. If the creature has infect however it deals damage as poison counters or -1/-1 counters. Equiping this bad boy onto an unblockable Blighted Agent makes him a target for removal, but also a guaranteed additional two poison counters for your opponent. Bladed Pinions also works well here by giving the equipped creature flying and first strike. The flying ability makes it more difficult to block the creature, and therefore more likely to get through to the player and give them a poison counter. The first strike affect is very useful with infect as the infect damage will also reduce the damage that the creature can do back to your attacker.
Ichorclaw Myr, Plague Myr, Contagion Clasp, Bladed Pinions, Livewire Lash, and potentially the Inkmoth Nexus), one additional artifact - the Throne of Geth is an excellent addition to this deck. This card allows you to proliferate poison counters to your heart's content, and is a great way of disposing of artifacts that are either of no use, or are being destroyed by an opponent.
I have included one planeswalker card in this deck too, 'Tezzeret, Agent of Bolas' because his abilities work in well with a deck that has a number of artifacts. The first ability allowing you to search for that specific artifact that you need, and the second one to change an artifact into a 5/5 creature is great for getting a big blocker, or making your Ichorclaw Myr really deadly.
The land cards in the deck are fairly self explanatory, all poison decks should have a complete set of Inkmoth Nexus cards, the Drowned Catacombs for versatility in a Blue/Black deck and the Burried Ruins are good for getting your artifacts back after they have been destroyed or sacrificed to the Throne of Geth.