{Descendants' Path}
It looks quite broken, but how to abuse it?
My first guess was in a bant miracles build, using cards like {Temporal Mastery} in order to
Get to 3 mana, the decks could run {Nest Invader} and {Emrakul, the Aeons Torn} combined with {Sensei's Divining Top} to cheat it out as early as turn 2