Brain Freeze

Set
Scourge
Rarity
Uncommon
Text
Target player puts the top three cards of their library into their graveyard. Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)
Legality
Legal in: Commander, Duel, Legacy, Penny, Vintage
Rulings
2013-06-07: The copies are put directly onto the stack. They aren’t cast and won’t be counted by other spells with storm cast later in the turn.

2013-06-07: Spells cast from zones other than a player’s hand and spells that were countered are counted by the storm ability.

2013-06-07: A copy of a spell can be countered like any other spell, but it must be countered individually. Countering a spell with storm won’t affect the copies.

2013-06-07: The triggered ability that creates the copies can itself be countered by anything that can counter a triggered ability. If it is countered, no copies will be put onto the stack.

2013-06-07: You may choose new targets for any of the copies. You can choose differently for each copy.