Asmodeus, Vagrant of Umbra

Flash, shadow (This creature can block or be blocked
by only creatures with shadow.)
Asmodeus, Vagrant of Umbra cost {1} less for
each creatures that dies this turn.
Whenever a player lose life this turn, you may
pay {1}. If you do create a 1/3 blue and black
devil nightmare creature token with shadow.
When a creature you control with shadow deals
damage to another creature, you may surveil 1,
then draw a card.