Savage Summoning | Magic: The Gathering
Formats Savage Summoning is Legal in
Official Oracle Text for Savage Summoning
The next creature card you cast this turn can be cast as though it had flash. That spell can't be countered. That creature enters the battlefield with an additional +1/+1 counter on it.
Official Rulings for Savage Summoning
7/1/2013 : If you cast multiple Savage Summonings in succession, they’ll apply to the next creature spell you cast. That creature will enter the battlefield with that many additional +1/+1 counters on it.
7/1/2013 : Spells that would counter Savage Summoning or the relevant creature spell can still be cast. They won’t counter the spell, but any additional effects they have will happen.