A theological excercise that resulted in the Council of Nicea issuing a bull that stated each of the trinitarian persons are a separate person with ine essence, that they are co-eternal, and constitute three roles of one being.
No. The Ghost always was the third person of the Trinity. The theological exercise led the Council to that conclusion.
I see. Theological exercise. It allowed them to say that they were "filled with the Holy Spirit" therefore acting on behalf of God.