Urgoth, Darkness Weaver

Urgoth, Darkness Weaver costs {1} less to cast for
each creature cards in your graveyard.
{t}{b/r}{b/r}{b/r}: Return target Nightmare from your
graveyard to the battlefield under your control,
except it is a 1/1.
Whenever a Horror you control dies, you may 3
life in addition to its mana cost. If you do, return
it to the battlefield at the beginning of the next
upkeep.