Sorry for the delay, just now saw this. My clarification to your last question is to fall back on the traditional understanding of evil, going back to at least

Sorry for the delay, just now saw this. My clarification to your last question is to fall back on the traditional understanding of evil, going back to at least Plotinus: evil is real, but it's a derivative reality, parasitic on good. So you can't have a being of pure evil: it's sort of ruled out (in this understanding) by definition. What you can have is a being that, through the good of free will, chooses lesser goods - in this case, itself - and in the process corrupts itself and effectively revolts against its Creator. Evil, yes, but not pure evil, and not originally created as such. It's not as if this line of defense doesn't have its holes, but it's plausible enough that I don't think it can be dismissed out of hand. And it also explains enough that, given my other philosophical and theological predispositions, I tend to think it (or something like it) quite probable.