Bosenwyn's Goatmaster

When Bosenwyn's Goatmaster enters the play, create a 0/1 Duskgoat. At the beginning of your upkeep, create a 0/1 Duskgoat.
{t}, sacrifice X goats, pay 2 life: a black creature you cast cost X less to play.
{t}, sacrifice X goats, discard a card: target creature or planeswalker gets a -X/-X counter on it.