Thune's Assassin

Fatewalk (When this creature comes onto the
battlefield choose one listed ability. Thune's
Assassin gains that ability until it leaves play):
{t}: Exile target creature black creature.
{t}: Destroy target Non-White with power of 4
or greater.
{t}: Destroy target Non-Blue creature with
casting cost 6 or greater.
In the Holiest of lands Assassins of royal blood are
trained ruthlessly, all to rid the world of the
greatest evils."