If Kaisa is conquering and Sky Splitter is in trash, can Sky Splitter be used with only 3 points (since Kaisa reduces cost by highest Might unit owned)? Can Defy counter this? Is the cost reduction applied before or after reactions?

Ruling: When a card references "Cost" (like Kaisa does), it only refers to the printed cost in the top left corner, not what was paid. Sky Splitter is always an 8 for those abilities, so it cannot be used with only 3 points even with Kaisa's cost reduction.

Nuances:

• Cost reduction from abilities like Kaisa's does not change what counts as the card's "cost" for other card effects
• For Bullet Time specifically, you pay the energy cost when adding it to the chain, but power costs are paid during resolution (so if countered, power is not paid)
• The Bullet Time timing is unique because paying power is part of the effect, not a cost of the spell