Complex sentence: Stunned by the vision and the sacred verse, Ahriman tumbles back into the realm of Darkness, where he lies prostrate, indifferent to his demons' efforts to rouse him from his depression.
Split into simpler sentences: Stunned by the vision and the sacred verse, Ahriman tumbles back into the realm of Darkness. There he lies prostrate; in vain, his demons try to rouse him from his depression.