Unwholsome pact

Sacrifice target creature you control. Put into play
a number of 1/1 black Spirit tokens with Flying for every Soul counters ther were on that creature plus one, then lose 1 life for every Spirit token put into play that way. All your creatures gain haste and Lifelink until end of turn.

"Yes, pathetic fleshling, you will have your army... but we ask for... something... in return"