mtg transform cards Bloodline Keeper | From the Vault: Ages 13+. Transforming Flourish MTG - Tarkir:

This was a deviation from the stated goal of pretending that there'd been six colors since the beginning, but it was inevitable because we needed a way to get the lands out to the casual crowd

And for the most ardent of Ravnica fans, double rainbow foil serialized versions of these Ravnica City treatment guild leaders are available as wellonly in Collector Boosters

Well, we're operating on the general principle of getting cards from your library to your hand in a fashion which generates card advantage

Its a big ask though, spending six mana, especially as the Apex Observatory enters tapped, preventing you from getting value from it until the next turn