The "Rot from Within" deck combines features of aggressive decks and combo decks into a winning package. It can come out of nowhere, delivering a lethal ten poison counters to a hapless opponent before he or she even knows what's going on. Inexpensive creatures like Glistener Elf and Ichorclaw Myr can sneak in a point or two of damage early, then rise to enormity thanks to cards like Groundswell,Primal Bellow, and Mutagenic Growth.
Some creature-based decks play out the same way every game, putting their threats on the table and attacking until the opponent is defeated. This deck, however, requires you to be more subtle. Your strategies may change based on your opening hand. Sometimes you'll have Glistener Elf on the first turn, two Groundswells in hand, and it's full speed ahead toward a turn-three victory. Other times you'll need to be more patient, waiting for your opponent to tap out and striking after a surprise Carrion Call. Still other games will see you doing basically nothing at all—until you're running over your opponent, tapped out or not, with a single Putrefax. Boosted by a Primal Bellow or two, it can easily deliver a lethal dose of poison counters!
Your power-pumping spells are one of your deck's greatest strengths, but your opponents may see it as a weakness. If your opponents are using their sideboards to make sure you don't have any creatures to pump up, bring in Trigon of Infestation to make sure you never run out of gas. Other decks may try to slow down your momentum with wave after wave of blockers. Between your Contagion Clasp and Unnatural Predation, however, you should be able to either get those blockers out of the way or trample over the top for lethal damage in spite of their best defensive eff orts. The rest of your sideboard consists of specific answers to specific problems— includingMelira, Sylvok Outcast, just in case your opponent also has poison in mind!
While this version of the infect deck tries to be as explosive as possible, there are other ways to go about building it. Stocking up on Inkmoth Nexus as your primary win condition allows you to perhaps dip into black and fill your deck with more removal spells. Alternatively, embracing black could lead you to more powerful creatures with infect like Phyrexian Crusader, Phyrexian Vatmother, and Hand of the Praetors.