Can Kai'Sa's legend ability pay for the power cost to hide Sprite Call?

Ruling: No, Kai'Sa cannot pay for hiding Sprite Call because hiding is not playing a spell, and Kai'Sa's ability only generates power when playing spells.

Nuances:

• Hiding a card is distinct from playing/casting it
• Sprite Call only requires energy as its cast cost, not power
• Kai'Sa generates power specifically for playing spells, which doesn't apply to the hide action