Cthulhu The Sea Demon

If you are attacked by any blue or black creatures
an opponent controls, you may pay {u/b} to destroy
or gain control of that creature.
{t}{ut} Destroy target creature and other {u} lands
are destroyed.
{u/b}{u/b}{u/b}{u/b}{u/b}{u/b}{u/b}: Destroy all blue and black creatures.
"Golly, it's Cthulhlu!" - Sailor, Last Words