For Bullet Time, when must the player declare how much power they are paying for the spell's effect - when the spell is played and placed on the chain (as a cost), or when the spell resolves?

Ruling: The power payment for Bullet Time is not a cost of the spell. The choice of how much power to pay and the actual payment happens on resolution, not when the spell is played and placed on the chain. The total cost to play Bullet Time is just 1 energy.

Sequence:

• Step 1: Pay the 1 energy cost to play Bullet Time
• Step 2: The spell is finalized and placed on the chain (no power amount declared yet)
• Step 3: When Bullet Time resolves, the controller declares and pays the power amount

Nuances:

• "Do X to do Y" wording is specifically omitted from targeting requirements in Step 2
• The power payment is handled as a choice made on resolution, not as an additional cost during the playing of the spell
• If the card were worded "as you play me, you may pay any power as additional cost," then the amount would need to be declared before finalizing onto the chain, but that is not the current wording