If Not So Fast is played against a Missile Barrage with Repeat targeting two units (or one unit twice), does it counter both effects or just one?

Ruling: Not So Fast counters the entire spell including all Repeat effects. Repeat does not add separate triggers, so the whole spell is countered as one.

Sequence:

• Missile Barrage is cast with Repeat effect
• Not So Fast is played in response
• The entire spell (both the initial effect and the Repeat effect) is countered

Nuances:

• This applies regardless of whether Repeat targets two different units or the same unit twice
• The spell is treated as a single spell with combined energy cost and power for purposes of cards like Defy