Neither.
Zoroark, of course, needs to have enough energy attached in order to use Foul Play, but that is the only energy requirement.
Of course, if the number and type of energy attached affects the results of the attack, then the energy on Zoroark would matter.
For example, if Zoroark was copying X Ball from Mewtwo EX, then it does 20 x the energy actually attached, not an infinite number, and not 20 x double the energy attached to the Defending Mewtwo EX.
Hope that helps.