A lot of Magic: The Gathering sets are themed around a specific location in its multiverse. Somewhere with a distinct identity like Innistrad, where it's all Hammer horror movie all the time, or Eldraine, a land of fairytales and legends. The next set is not one of those. March of the Machine is an event set, which is something we haven't seen since War of the Spark back in 2019. It's taking place on a bigger scale, representing the climax of a storyline that's run over the last three expansion sets.
Where things left off in the previous set, which took place in the biomechanical hellscape of Phyrexia, the Mother of Machines seemed to have won. Elesh Norn's plan to launch an invasion across multiple planes simultaneously using a corrupted cosmic tree called the Realmbreaker was successful, and her Machine Legion was poised to conquer and convert the multiverse, borg-ing the inhabitants of world after world, turning them into porcelain-and-metal Phyrexians to conquer yet more worlds with.
