Genbu of the Water Ashari

{4}{u}{g}: Look at the top 5 cards of your library.
You may reveal a Beast, Kraken, Turtle,
Leviathan, Octopus, or Serpent card from among
them and exile it. If you do, Genbu of the Water
Ashari becomes a copy of that card except for
that it gains this ability. You may only activate
this ability any time you could cast a sorcery.