In Shakespeare's play "Macbeth", Claudius is not a character; however, in "Hamlet," Claudius is the main antagonist who becomes king by murdering his brother, Hamlet's father. Throughout the play, Claudius is indeed plagued by guilt due to his conscience. After committing the regicide, Claudius struggles with the weight of his actions and the guilt of his crime. His guilt is evident in his soliloquies where he expresses remorse and acknowledges the enormity of his sin. Claudius's guilt and conscience play a significant role in the unfolding of the plot as they contribute to his eventual downfall.