Magic: The Gathering – Magic OriginsExpansion

From BoardGameGeek:

Magic Origins was released on July 17, 2015. Magic Origins told the origin stories for 5 planeswalkers who are featured in sets after Origins. It featured a cycle of double-faced cards (originally used in Innistrad) that have a legendary creature on one side representing the character before their transformation, and a planeswalker on the reverse face that represents them after gaining their new power. The set introduced the mechanics of renown, spell mastery, and menace. It also features cards with the prowess mechanic, which was introduced in Khans of Tarkir block, and the scry mechanic, which was introduced in Mirrodin block. In February 2015, Wizards of the Coast said that it would be an introductory product "like a core set", and it was published in the time period that a core set would have taken up during the pattern established by Magic 2010. After Origins, Magic switched to a new schedule where each year contained 2 blocks, and each block contained 2 sets. With the new schedule, there are no announced plans for a major "standalone" set like Origins that is not part of a block.