Power. That's what you two will generate when you're together, and just like electricity itself, you'll have to be extremely careful as to how you direct it. The energy, passion, and, yes, anger you'll inspire in each other could consume you if you aren't careful.
It will help if you and your friend are both emotionally stable people, because this connection may bring out your dark side. You'll tap into your friend's natural energy, and they'll tap into your own deepest source of power, but in a way that could create conflict. There's a dangerous, risk-taking quality to your particular union. Projections will run rampant between you, and you might even enjoy provoking your buddy on purpose, just to get a reaction! But that's a bad idea, because this relationship has lots of potential for aggression, anger, and even rage. If anger overtakes you, you'll find it really difficult to stay rational. Try to stay levelheaded and talk out your feelings calmly rather than engaging in psychological warfare. Otherwise, this relationship could degenerate into little more than an ongoing power struggle. You'll both need to remind yourselves often that the only person you can or should control is yourself.