Our first precon deck for Dominaria United is the RWB Legends' Legacy precon. It has a legends-matter theme, with some tokens and reanimator synergies. Joining Dihada, Binder of Wills into the annals of history is the premier sleeper agent hunter of the New Coalition. Decklist is here.
As a longtime (almost ten years) Reki player, Shanid has me pretty stoked. The fact that this triggers off lands is huge. Works with legendary creatures and artifacts, of course, and also with legendary sorceries from OG Dominaria.