Dreaming about a mysterious person you were in a relationship with can symbolize various aspects of your life or emotions. Here are some possible interpretations:

1. Exploration of the Unknown: The mysterious nature of this person may represent aspects of yourself or your life that you are not fully aware of yet. This dream could be an invitation to explore your own feelings, desires, or hidden aspects.
2. Desire for Connection: If you are currently feeling lonely or disconnected, this dream might reflect your longing for intimacy or a deeper emotional connection with someone.
3. Unresolved Feelings: If you have unresolved relationships or feelings in your waking life, the mysterious partner could embody those emotions or represent someone from your past.
4. Change and Transformation: Mysterious figures often symbolize change. This dream may indicate that you are undergoing a transformation in your personal life or emotional state.
5. Intuition and Inner Wisdom: Sometimes, a mysterious figure can be a manifestation of your intuition or inner wisdom. Consider what feelings this person elicited in the dream, as they may guide you to clarity in your waking life.

Reflect on your current feelings and experiences to gain more insight into what this dream means for you personally.