Repulse

spell

[Reaction] (Play any time, even before spells and abilities resolve.) Choose a friendly unit at a battlefield. Counter an enemy spell or ability that chooses it and no other friendly unit.

Rulings

• I play Alpha Strike targeting my Master Yi, Unstoppable and splitting 12 damage among three of the four enemy units at battlefields. If my opponent plays Flash in reaction to my Alpha Strike, moving two of the targeted units to base, can they then play Repulse and counter my Alpha Strike?