I am pretty sure that Crayak is based on Sauron and is a big red eye...
the difference between Crayak vs Ellimist and God vs Satan is that God is much more powerful than Satan. A story that illustrates this was told about Martin Luther by my religion teacher. When Martin Luther was translating the Bible into german whilst locked up in a castle for his own protect, he was having a terrible depressive episode (he is often retroactively diagnosed as being Manic Depressive/Bipolar) and was toss and turning and having the sensation of having his chest crushed, he woke up and saw the devil standing at the end of his bed. When Luther saw this he said "oh it's only you" and went back to sleep. My teacher said that what story meant was that people give the devil far too much credit (which he likes) and blame him for their evil actions rather than take responsibility (like David Berkowitz and a few other serial killers). The devil is basically a pathetic coward with little power beyond that of tempter. where as the Crayak and Ellimist are evenly matched which ties the Crayak and Ellimist into being more Mandaean or Zoroastrian.