Geez, @improv, you're a wild one aren't you? I was like how'd we get to Shakespeare?
That's a good thing, by the way ;)
Hmm I think you're right, I mean you can argue that he would've eventually killed Banquo and Macduff's family as well, but you just never know. You ask an excellent question - did the witches "make" Macbeth do it or would he have done it anyway?

But, since we both agree he might've killed Duncan of his own accord, who's to say he wouldn't have eventually gotten the idea to kill the others as well? Maybe the witches were just a catalyst for something that would've happened anyways.

Anyhow, really really nice work. I loved reading this. I'd give ya the latest prompt, but I see you've done it already ;)