Which characteristic of macbeth's most directly affects the theme of this scene act 1 scene iv

I believe that Macbeth's character change is too extreme. From being a loyal subject and essentially a good man, he becomes a terrible tyrant, and in the end he is behaving like a madman. It was not logically necessary for Macbeth to turn into such a hateful tyrant just because he committed a murder to become king. 

1. canadian → ned land  2. resolving action → denouement3. narrator of twenty thousand leagues under the sea → pierre aronnax  4. novel of manners → social class   5. planned action → plot  6. samuel pepys → diary  7. omniscient; first-person, limited → point of view  8. ivanhoe → historical novel  9. robinson crusoe → novel of incident  10. abstract idea → theme of novel