The investiture of Ardashir shows him receiving the ring of Kingship from Ahura Mazda (on the right).
The Roman Emperor Julian is shown beneath the feet of Ardashir II who he defeated and killed in 363 AD.
Of particular interest is Mithra standing on a lotus flower and holding a Barsam.
As always Mithra is portrayed with the undying son behind his head.
Links to Mithra have been found in many religions including the Roman Mithraism (Sun God) and Manichaeism.