you could also use the supernatural involvement, i guess. the witches prophecy gave Macbeth the false sense of security, since he wasn't going to be killed by "one born of woman" or whatever it was. which helped bring his downfall.
maybe also something of the honor. you could compare Macbeth to Macduff for this, but i'm not too sure if there's many relevant quotes for this in that particular part of the play... i think there's also something about honor of fighting and dying in battle...
destiny could be another. you could argue about how Macbeth's destiny was finally fulfilled despite what he believed.
i don't remember too much about the play, and i wish i could help you more, but i'm currently cramming last minute for my final tomorrow.
well, cheers, and i hope i helped you out a bit!