What happens if you Gust a unit that your opponent declared as a target for Baited Hook? Is killing a unit with Baited Hook a cost?

Ruling: The target is declared when Baited Hook is activated, so you can react with Gust on that unit. If the unit is gone when Baited Hook resolves, the might is returned as "null" and they can't play a unit.

Sequence:

• Opponent activates Baited Hook and declares the target unit
• You can respond by playing Gust on the targeted unit
• When Baited Hook resolves, if the unit is gone, the might return fails and no unit can be played

Nuances:

• Killing the unit is not a cost (costs are before the ":" in card text)
• The targeting happens when the ability is put onto the chain, not during resolution