Can you Gust a unit at a Battlefield that is being killed by Baited Hook to prevent the opponent from getting a new unit?

Ruling: Yes, if the unit is a valid Gust target, you can Gust it in response to the Hook trigger on the chain. The Hook will still resolve, but since the target left the field, it will not successfully kill anything and the opponent will not be able to play a new unit.

Sequence:

• Baited Hook's trigger is placed on the chain (after paying costs including exhaust, 1 energy, 1 order power)
• The target unit is chosen as the ability is placed on the chain
• You can React with Gust on that chain
• If Gust removes the target, Hook still resolves but fails to kill the target
• No new unit can be played from the revealed cards

Nuances:

• Under current rules, Hook resolving with no valid target would produce a might value of 0, allowing a unit with 1 or less might to be played (though this is rare)
• After an upcoming Comprehensive Rules update, failing to resolve a target will produce "null" (no valid value), meaning no unit could be played at all
• You cannot choose a new target if the original target is removed, as targeting happens when placing the ability on the chain, not upon resolution
• The costs of Baited Hook must still be paid when activated, regardless of whether the target is later removed