March of the Machine is the dramatic conclusion to the Phyrexian story arc. The entire Multiverse rallies together in one epic climactic battle.
Draft, Set, Collector, and Jumpstart boosters all return as pack options. As for art treatments, Extended Art and Borderless art treatments also return, while characters in this set get a feature "Showcase" art treatment each from their home plane. Phyrexian Praetors return with new double-faced cards that appear in normal, showcase, and serialized borderless versions. Each booster pack also contains at least one "Multiverse Legends" card; a reprinted iconic character in their home planes' "Showcase" treatment. These legendary creature cards appear in nonfoil, halo foil, foil etched, and serialized double rainbow foil versions. Each Commander Deck for this release includes 10 oversized Planechase Planes. [source]
