If you and your buddy are both stable people, this aspect could be an incredible boon for your relationship, but it could also bring out your dark side. In a word, this aspect will bring power to your connection. When you join forces -- on a project, during sports, in an argument, whatever -- you'll tap into your friend's natural energy, and they'll tap into your own deepest source of power.
You know the expression 'the earth moved'? That's you two, when you combine your efforts -- so be careful about how you apply those efforts! When you two are in conflict, watch out! If you permit anger to overtake you, you'll find it really difficult to stay rational. That's part of the potential for trouble, in fact: You might lose sight of what's real and simple and expected when you tap into those deep, dark emotions. Let's hope you're both levelheaded enough to talk out your feelings calmly rather than engaging in psychological warfare. If you aren't careful, this friendship could degenerate into little more than an ongoing power struggle.