The Ixalan block will be composed of the large expansion Ixalan and the small expansion Rivals of Ixalan . Ixalan block is the last block before the introduction of the Three-and-One Model.
On December 9, 2016 an official Wizards of the Coast survey showed packaging design concepts for Amonkhet, Hour of Devastation and two previously unknown sets: Atlazan and Conquest of Power. On the same day Blake Rasmussen performed some damage control in the Daily Magic Update, implying that the real names for the sets would be revealed on Announcement Day.
The Ixalan block doesn't come with a Masterpiece Series. The Explorers of Ixalan supplemental set is thematically connected, but isn't part of the block.