If an opponent moves a 1 might unit into a battlefield on their turn, can I play Bellows Breath to kill it? Can they react with Ride the Wind to avoid the Bellows Breath?

Ruling: You can play Bellows Breath to kill the unit, but your opponent cannot respond with Ride the Wind because both are Action spells. Action spells can only be played in an open state (when the chain is empty), so your opponent cannot play an Action in response to your Action.

Sequence:

• You play Bellows Breath targeting the unit, placing it on the chain
• The game state becomes closed (chain is active)
• Your opponent cannot play Ride the Wind because it's an Action spell, not a Reaction
• Bellows Breath resolves, dealing 1 damage to the unit
• The unit dies (assuming it has 1 might)
• The chain empties and game state returns to open
• Priority passes to your opponent, but the unit is already destroyed

Nuances:

• If the unit somehow survived the Bellows Breath damage and focus was passed to the opponent after the chain resolved, they could then play Ride the Wind as a new Action in the now-open game state
• Only Reaction spells can be played in response to spells already on the chain; Action spells require an empty chain