Hecate is the goddess of the three witches. She directs the supernatural happenings and appearance of mystical spirits. Hecate was angry because the witches played tricks on Macbeth without her knowing or being involved. She wanted to be involved in the destruction of Macbeth, and was angry that they did not include her. She wanted to contribute to his end because she felt satisfaction for knowing she ruined someone. I think Shakespeare used her because she contributes to the end of Macbeth.
