What is "lorwyn"

The Lorwyn block is a Magic: The Gathering expert-level block consisting of two sets: Lorwyn (October 2007). and Morningtide (February 2008). A third set, codenamed "Jelly", was originally planned as part of Lorwyn block, but partway into the design of Lorwyn, that block was changed to a two-set block. Jelly was revealed as Shadowmoor, the first set of a second two-set block. The two blocks were linked through synergy and rotated through the official tournament formats as a single, four-expansion unit. The primary theme of the Lorwyn block is tribalism.