In Macbeth, Shakespeare demonstrates a human beings true nature. Shakespeare shows the evil intent and malice that is in someone no matter how hidden. Macbeth is no exception, even though he started honorable being worthy to be moved up rank he soon changes when his greed for power surfaces. With this in mind, I believe a theme befitting for Macbeth is the evil in someone's heart can change people.
In the play, there are various of scenes that can relate to other movies. One movie would be the Disney's Princess and the Frog. In both Macbeth and Princess and the Frog someone is controlled by their greed for power to the point of no return. In Macbeth it is when Duncan is killed by Macbeth for the crown. In Princess and the Frog it is when the prince's servant turns the prince into a frog for wealth and more power. In both scenarios, this greed leads both villains to their demise and ironically taking away all their power that they sacrificed everything for leaving them with nothing. This helps support the theme that evil in someone's heart can change people.
Princess and the Frog and Macbeth also use misconception to lead the servant and Macbeth to disaster. Both seem to use fortune telling to first fuel their greed. Princess and the Frog has the Shadow man who is similar to the 3 witches, the Shadow man basically tells the servant that if listen and does what he says then he can become wealthy. As for Macbeth, the 3 witches tell him about he will become king leading him to his actions. Both characters are fooled by the fortune telling because they soon turn greedy without knowing the whole future. If the witches planned to trick Macbeth then it could be said that it is the evil in the witches that changed Macbeth like how the evil in the Shadow man changed the servant, continuing the theme.
Another similarity in both stories is manipulation. In Macbeth, Lady Macbeth manipulates Macbeth pushing him to the edge to kill Duncan knowing if he does then he may be able to become King. In the Princess and the Frog, the Shadow man also manipulates the servant since if his plan works out then he can have the shadows roam New Orleans. Both stories manipulation changes the characters into villains showing the hidden evil intent in people.
Similarities are clear in these two stories but they do share their differences. One visible difference is the endings, Princess and the Frog ends in happily ever after with the villain behind bars unlike Macbeth which has a more tragic ending with Macbeth's death. The two stories are actually different yet also similar sharing the theme, evil in someone's heart can change people, in different scenes. Therefore the theme evil in someone's heart can change people is not only important in Macbeth but also in other movies.