it's important to remember that Constantine overturned Nicea later with the Synod of Tyre and banished Athanasius while restoring Arius to good graces. The "Orthodox" had to wait until he died off before they overturned the Synod of Tyre with the Council of Constantinople.
....and Arius taught 'God is unbegotten and without a beginning. The Son,
because he is begotten can not be God in the sense that the Father is.
The Son did not exist from all eternity but was created and exists by the will of the the Father.'
-Rev 3v14 B