In the DMM version of the game they come with rewards based around the Blooming system from what I understand, much like our Bloom Dragons. Bloom Dragons for evolution/1st evolving, some type of Bird/Feather if I'm not mistaken for Blooming/2nd evolution.
Most Bloomed evolutions are for 6* units, from what I've read.
Since we're not "There yet" in terms of our updates, right now they're just missions with a FG attached to them.