1. The Cycle of Kingship: The procession of kings represents the long line of Scottish monarchs that precede Macbeth and the cyclical nature of kingship. It suggests that every ruler will eventually be replaced, and that Macbeth's time as king is limited.
2. Macbeth's Guilt and Isolation: The mirrors held by the seven kings reflect back Macbeth's crimes and guilt. They represent the constant reminder of his actions and the internal turmoil he's experiencing. The fact that Macbeth sees himself in the eighth mirror highlights his isolation and separation from the other kings.
3. The Consequences of Macbeth's Actions: The final apparition serves as a warning to Macbeth about the inevitable consequences of his actions. It foreshadows his downfall and suggests that he will be held accountable for his crimes.
4. The Delusion of Power: The appearance of the final apparition challenges Macbeth's belief in his absolute power. It reminds him that there are forces beyond his control and that his rise to power has come at a great cost.
5. The Supernatural and Symbolism: The final apparition is steeped in the supernatural and the use of symbolism. It adds an element of mystery and the unknown, reinforcing the play's exploration of fate, prophecy, and the supernatural forces at work.
Through this final apparition, Shakespeare conveys the themes of cyclical power, guilt, isolation, consequences, and the illusion of power. It serves as a haunting and chilling representation of Macbeth's journey and the ultimate downfall that awaits him.