But quite a few words mentioned are clearly Iranic or Persian. Kurds are Iranian people too. Words such as Pir, Yazada in turn Izad - they're definitely old Persian and also used in Zoroastrianism. But more so Mithraic (aryan pagan), the religion common among Aryans (by extension Persians/Kurds/other Iranians) before Zoroaster/Zoroastrianism.
It fairly clear they've strong Islamic influence (perhaps culturally more so than linguistically). Not so sure about links to Christianity or Judaism. Though, it can be that their religion evolved over time, beliefs & practices were modified or added.
Nestorian (Church of the East) is mentioned; that's the ancient church dating back to the Sassanid period in Iran (pre-Islam). Cronos probably knows about the Nestorian influence.
I can't figure out the "Peacock Angel" & how it's related to Satan or Lucifer as others associate the two. There is no such thing in Zoroastrianism or even in Mithraism. The closest I can think of is a mythical bird called "Simorgh" (equivalent of Phoenix); though has nothing to do with the devil.
Yazidism is definitely a mish mash of different religions. I was trying to find out more last night; some strange concepts & beliefs.
Also, the above statement makes no sense & is invalid to justify ISIS' attempted genocide of Yazidis.
Yazid 1 per above quote from the BBC article/link, was a Sunni & 2nd Caliph after Mohmmad's death in Sunni tradition. He beheaded Hussein (the 3rd Shia imam) who was Mohammad's grandson, son of Ali ibn talib the 1st Shia imam.
Shi'ites in Iran & Arab world revere Hussein, especially during Ashura mournings. So, it makes no sense for ISIS, who are essentially Sunni (ok, mostly Salafi but still Sunni), to hate Yazid & therefore Yazidis, even if there were a link between the two!