April 18-24: Third Set Prereleases!
April 23, 2006: Dissension Prerelease
In this final expansion set in the city-plane of Ravnica, players were introduced to the final three guilds of the block: the Azorius Senate (blue-white), the Cult of Rakdos (black-red), and the Simic Combine (green-blue), as well as the secret of the district of Agyrem, the Ghost Quarter.
April 21, 2007: Future Sight Prerelease
The quest to mend Dominaria’s temporal and planar damage continued. A temporal rift connected to an alternate Dominaria has enabled Phyrexian horrors to cross over into the present day. Freyalise was gone, having given her planeswalker spark and her life to close that rift, thereby protecting her sanctum of Skyshroud one last time. The Time Spiral block reached its climax in this set from an alternate (but possible!) future. Future-shifted cards hinted at mechanics and worlds yet to come.
April 20, 2008: Shadowmoor Prerelease
Shadowmoor was just last year. You remember it, right? Wither, Persist, the untap symbol? Plenty of hybrid cards? Look, it's still Standard-legal. You must remember it.