If a hidden Blastcone Fae is in a battlefield and an opponent plays Unchecked Power to kill a unit in that battlefield, can you react to the unit dying by flipping Blastcone Fae to keep a unit in the battlefield?

Ruling: No, you cannot react to the unit dying by flipping Blastcone Fae to keep a unit in the battlefield.

Sequence:

• You can react before Unchecked Power resolves (but then Blastcone Fae would die to the spell)
• Or you get priority after Unchecked Power resolves (but by then your unit is already dead and the hidden card is already in the trash due to cleanup after spell resolution)

Nuances:

• Hidden cards are sent to trash during cleanup after spell resolution, before you get priority again