Cardigan, Bleak Composer

Cardigan, Bleak Composer enters the battlefield
with X melody counters on it.
At the beginning of each player's end step, if that player controls no creatures, put a melody
counter on Cardigan, Bleak Composer and put a
1/1 spirit token onto the battlefield under that
player's control.
{b}{r}{t}: Destroy all creatures with mana value
less than or equal to the number of melody
counters on Cardigan, Bleak Composer, then
remove a melody counter.