Macbeth's guilt started when he killed King Duncan. Although he had regret of what he had done, Macbeth keeps committing crimes, such as killing Banquo, and eventually greatly suffers from guilt. Lady Macbeth, who encouraged Macbeth to murder people, cannot stand the guilt that she feels and goes insane. She ends up committing suicide, not able to stand the guilt anymore. Macbeth's want to become a King turned him from a fearless and a heroic soldier to a bloody murderer.