Lightning Symphony

Whenever an instant or sorcery spell you
control deals damage to a creature, put a
crescendo counter on Lightning Symphony,
then it deals X damage to that creature's
controller, where X is the number of
crescendo counters on Lightning Symphony.
Then if there are four or more crescendo
counters on Lightning Symphony, sacrifice it
and it deals 10 damage to each creature, player,
and planeswalker.