The power says it grants the use of one of its powers to the subject.
Does the power use the spirit's attributes for determining the effects of the powers?
Or the subject that is being endowed?
For instance. A mage with a magic of 5 and charisma of 5 Invokes a Force 1 Task Spirit. Since it is force 1, it wont be too hard for the Mage to get enough hits on the Invoking roll to get one of the optional powers (influence, 3 hits) greater power (Endowment, 5 hits).
Then the mage uses a service to have the force 1 task spirit grant him use of Influence. Since he is granted the power. Does he roll 10 dice (his magic+charisma)? Even though the task spirit granting the power is only force 1.