The song mentions that no one can stop him, and that is what Macbeth thinks. Also, the song is portraying confidence that no one will get in his way. A characteristic of Macbeth is confidence. He first gets confidence from the witches by the witches told him that he would become Thane of Cawdor and become king. He became Thane of Cawdor, so he thought he would become king. After he becomes king, the witches give him confidence again by tricking him and telling him that he is invincible. After Macbeth realizes that he was tricked, he fought Macduff to the death and ends up dying. A line from the song says that they will fight till its over, and by over for Macbeth, it means the end of his reign and life.