Triforce of Love
This Triforce is built around the triangular theory of love. This is the theory that love has three components. The components are intimacy, passion, and commitment.
Intimacy - Which encompasses feelings of attachment, closeness, connectedness, and bondedness.
Passion - Which encompasses drives connected to both limerence and sexual attraction.
Commitment - Which encompasses, in the short term, the decision to remain with another, and in the long term, plans made with that other.
When all three pieces come together, this forms consummate love.
Consummate love - The complete form of love, representing an ideal relationship which people strive towards. Of the seven varieties of love, consummate love is theorized to be that love associated with the "perfect couple."
The Triforce of Love represents Dan and Madeline's love and the ring is a symbol of that love.