Dragon Feeding

Dragon spells you cast cannot be countered, have devour 3, cost {1} less to cast,
and enter with a +1/+1 counter.
Whenever a Dragon enters the battlefield
under your control, any opponent may pay {p/g}{p/r}.
If they don't, target opponents sacrifices a nonland permanent they control and the creature
cast this way enters the battlefield with an
additional +1/+1 counter.