Can floated runes be combined with newly exhausted runes to pay for a unit's energy cost?

Ruling: Yes, floated energy can be combined with newly exhausted runes to pay for a unit's total energy cost.

Sequence:

• Float energy from runes (e.g., 2 energy)
• Spend other resources if needed (e.g., power for abilities)
• Exhaust additional runes to combine with floated energy to meet the total cost (e.g., 2 floated + 2 newly exhausted = 4 total energy for a 4-cost unit)