Rottenmouth Viper (BLB-107) - Bloomburrow [Mythic]

As an additional cost to cast this spell, you may sacrifice any number of nonland permanents. This spell costs less to cast for each permanent sacrificed this way.
Whenever Rottenmouth Viper enters or attacks, put a blight counter on it. Then for each blight counter on it, each opponent loses 4 life unless that player sacrifices a nonland permanent or discards a card.