We all know the story of the prince, or princess that kisses the frog.  Your relationship has gone the other way.  Your partner is turning from the prince/princess into the beast.  The How did the most wonderful person in the world become the monster from the deep? 
 
It only takes one person to influence a relationship.  You, by yourself, can make a difference.  It is your choice whether you chose to learn and apply the skills, regardless of what your partner does.  That is right, you alone can make a difference in changing the dance.
 
This means you don’t need to depend on your partner to make a big difference in your relationship.  Applying relationship skills and caring can turn an argument into a productive conversation.  For example, how to listen without interrupting, or how to listen without preparing what you want to say next.  How to deeply love your partner enough to understand what they see, understand, want, and what emotions arise, even if you really disagree.  The problem, though difficult, is productive because of the way you worked together to bring about the resolution.