Can you use Defy on a spell that has a base cost of 1 power but costs 2 or more power due to Deflect?

Ruling: No, Defy only cares about the base cost of the spell, not the actual amount of power paid. Effects that specify "cost" refer only to the base cost, regardless of additional costs like those from Deflect.

Nuances:

• This principle applies generally to all effects that specify "cost" - they refer to base cost only, not the total amount actually paid