if you believe that satan is an actual being, just like god is an actual being, then the question i have for you is, who created satan? not god, the creator of everything?
if you believe that god initially created lucifer, and then at some point sin/evil was found in lucifer, turning him into satan, then how do you explain the origin of the evil that was found in lucifer??? obviously you wouldnt agree that an omnibenevolent god "pulled an inside job" placing evil in lucifer, or creating lucifer with an evil seed that later came to fruition, turning him into satan. so how do you explain??
i already know what you are thinking.... free will, right? ok, make your case on how its lucifer's fault because he had free will.. etc..... id love to travel down this road with you and see where it leads....
other explanations are of course welcome too.