Spoilers ahead.
We know it is set in Persia but what about the time period?
I have seen Mesopotamian (Sumerian, Assyrian, and Babylonian), Ancient Persian (Achaemenid, Parthian, and Sassanid), Safavid, and Qajar influences.
But as I see in the wiki, it says about a King named Darius which in Achaemenid was the name of various monarchs like Darius I also known as the Great (he ruled from 522 to 486 BC) who was known by his military campaigns in Scythia, the Indus, and the Balkans, Darius II (who ruled from 423 to 404 BC), or Darius III (who ruled from 336 to 330 BC, he was the last of the Achaemenid dynasty of Persia who was defeated by Alexander the Great.