Complex sentence: This figure represents Izad Bahram, who, in all the extraordinary adventures of Ardashir, performs the role of guardian and guide angel, just as before that, Izad Mithra (Mehr) was the guardian god of the Parthian military.
Split into simpler sentences: This figure represents Izad Bahram, who, in all the extraordinary adventures of Ardashir, performs the role of guardian and guiding angel. Previously, Izad Mithra (Mehr) had been the guardian god of the Parthian military.