Pumpkin bomb

As additional cost sacrifice a pumpkin and pick
order of three targets. Pumpkin bomb can only
target creatures with seed counters on them.
Pumpkin bomb targets creature and deals damage
to that creature equal to number of seed counters
on it. Then deals to second target damage equal
to seed counters on it plus first target. It then
deals damage to third target equal to seed counters
it has plus first two.