Destroy all creatures. They can't be regenerated. For each creature destroyed this way, its controller creates a 1/1 white Spirit creature token with flying.
Illustrated by Marc Fishman · Planeshift · #10
There are no rulings for March of Souls.
Destroy all creatures. They can't be regenerated.
Threshold — If there are seven or more cards in your graveyard, instead destroy all creatures, then create two 1/1 white Spirit creature tokens with flying. Creatures destroyed this way can't be regenerated.
Destroy all lands or all creatures. Creatures destroyed this way can't be regenerated.
You may cast this spell as though it had flash if you pay more to cast it. (You may cast it any time you could cast an instant.)
Destroy all creatures that aren't enchanted. They can't be regenerated.
Destroy all creatures. You gain 1 life for each creature destroyed this way.