Pallanneth, Sublime Light

Flying
Other Sphinxes cost you {1} less to cast if you
have four or more sorcery cards in your graveyard.
Other Sphinxes cost an additional {1} less to cast
if you have five or more instant cards in your graveyard.
Other Sphinxes can't be countered if you have
six or more instant and sorcery cards in your graveyard.