Ixhel, Scion of Atraxa
An Abzan infect and proliferate deck led by Ixhel, Scion of Atraxa, spread poison counters through infect creatures, proliferate them to ten, and win through the infect kill condition before opponents can stabilize.
New Phyrexia at full strength. Two decks: an Abzan poison deck and a Boros token army.
Toxic N gives the defending player that many poison counters on damage, and ten poison counters lose the game. It is a second, much shorter life total, and the Abzan deck is built to close it out.
Infect deals damage to players as poison counters and to creatures as -1/-1 counters. Older and more feared than toxic, and the deck runs both.
Corrupted abilities switch on once an opponent has three or more poison counters. It gives the poison deck a middle game payoff instead of an all or nothing race to ten.
Proliferate adds one more of each kind of counter already present, including poison. It is how the deck gets from three poison counters to ten without landing another attack.
Phyrexia: All Will Be One is the poison set, and the Abzan Commander deck is one of the few precons ever built to win by an alternate loss condition. Poison plus proliferate is a real clock, and tables that have not seen it tend to underestimate it until it is too late.
Corrupted is the design that makes the poison deck work rather than embarrassing itself. Getting an opponent to three poison counters is easy, and from there the deck gets extra value on every attack instead of needing to reach ten before anything happens. Proliferate covers the last stretch, which is why the deck can win from what looks like a harmless board.
The Boros deck is the counterweight: a straightforward token aggro deck for players who would rather not track two life totals. It also gives the box a second commander that plays fine in a pod that has agreed to leave poison alone.
Corrupting Influence is the more distinctive deck by a wide margin, and the one worth owning if you want a plan the table has no practice defending. Say so before you sit down, because poison changes how everyone has to block for the whole game.
Ixhel, Scion of Atraxa
An Abzan infect and proliferate deck led by Ixhel, Scion of Atraxa, spread poison counters through infect creatures, proliferate them to ten, and win through the infect kill condition before opponents can stabilize.
Neyali, Suns' Vanguard
A Boros token-aggro deck led by Neyali, Suns' Vanguard, create legions of creature tokens, give them double strike when they attack in multiples, and overwhelm opponents through explosive combat phases.