Sikes plays a crucial role in the plot as he is involved in several major incidents, including the attempted burglary of Mrs. Maylie's house and the murder of Nancy. His actions directly impact Oliver Twist's journey and shape his experiences throughout the novel. Despite his negative traits, Sikes is not entirely one-dimensional. He occasionally displays moments of human emotion and vulnerability, particularly towards Nancy. However, his violent nature and criminal behavior ultimately lead to his downfall.