Desperate Gambit
Weatherlight — uncommon
Instant
Desperate Gambit rulings:
2008-04-01: The chosen source may be a permanent, a spell on the stack, or anything referred to by something on the stack (such as a Prodigal Pyromancer that’s left the battlefield while its ability is still on the stack)
2004-10-04: The coin is flipped during resolution of this spell, so you know in advance what will happen when the source deals damage the next time.