Mar. 29th 2011 - Today Wizards announced that 'Action' is indeed 'New Phyrexia.' Check our spoiler page out at: New Phyrexia Spoilers

We now have a full spoiler of Mirrodin Besieged, the tipping point that will lead to the war being 'won' in the third set of this block.

But who will win?

This block was designed  with full knowledge of what side would be dominating the third set, so naturally clues were dropped along the way. Obviously, most of these clues seem to be thematic, or flavor-based.

According to the cards in both Mirrodin Besieged and Scars of Mirrodin, we can figure out the following: The Phyrexians have completely corrupted Geth and Glissa, and re-purposed SEVERAL Mirran locations and beings for themselves. The creature that, back in its day, was the biggest, baddest creature in print has even succumbed to Phyrexian infection, and is now reborn in the form of Blightsteel Colossus. The planeswalker Karn, who was the accidental source of the Phyrexian invasion originally, is imprisoned in Mirrodin's Core and is in the process of being turned into the leader of all Phyrexian forces.

So, how can Mirrodin win?

As far as I am concerned, they need to pull some Deus Ex Machina to win out. (That is, they need to have some aid, or weapon, come out of nowhere in the third set that magically beats the Phyrexians. Maybe the Mirrans find they are allergic to Chimney Imps or something.) Back in Apocalypse, to beat the Phyrexians, it took Urza orchestrating a complex genealogy project for generations and the assembling of the Legacy Weapon. Planeswalkers were also more powerful in those days, and they still needed these types of 'magical outs' to defeat the Phyrexians.

The Mirrans' strategy is that they are trying to outnumber the Phyrexians, which seems impossible given their nature. While the Phyrexians are trying to convert and overpower the Mirrans, infecting them and making them join the collective.

Story and flavor aside, there are other reasons the Phyrexians should win. The third set has 175 cards. Judging by what we see in MBS, we can expect another 10 basic lands to show the state of the landscape at the tail-end of the war. 165 cards is 20 more cards than a usual third set. Scars had 226 cards with watermarks in the set, at a split of about 80% Mirran, 20% Phyrexian. To make the entire block full circle, and even, the third set could be 80% Phyrexian 20% Mirran. That makes for slightly less for each faction than in Scars, but the larger set size buffers that a little.

In the Mirrodin Besieged expansion symbol, a combination of the two emblems, the Phyrexian part of it comes to a point in the middle, unlike the symbol shown for 'New Phyrexia'. This type of stylistic change helps differentiate between the two sets, and also shows that some thought was put into the Phyrexian expansion symbol, giving some credibility to it being the actual set's symbol. Meanwhile, the 'Mirrodin Pure' symbol is just a copy-paste of the Mirran emblem with nothing different or special about it.

The most valid argument about the third set being New Phyrexia is that infect would be too good. I can understand that. I don't think they will have much, if any infect in the third set. Flavor-wise, they have won. They assume most are already infected. So what mechanic comes around? Poisoned. Previewed in Besieged, it will naturally be used more in the third set. It allows it to still support infect strategies without making tons and tons of creatures with infect to overwhelm the format. Besieged also had spells that give poison counters to the opponent. We may see spells in Besieged that give yourself poison counters as a cost, or even those that benefit YOU if YOU are poisoned.

This block is not 'the poison block' or 'another artifact block'. It is all about the war between Mirrodin and Phyrexia. Therefore, the outcome is weaved into the cards. We just need to look closer.

Update: Here is MaRo's tweet on the matter.