The mental effect you have on each other is strong, but it isn't necessarily pleasant. There is an air of intensity when you're together, and you push this person to confront the deepest, most complex and potentially frightening issues in their life -- their past, for example, or their attitudes about death, sex and spirituality. The way that you try to force them to face these issues and ferret out their deepest, most buried emotions is probably going to be pretty uncomfortable for both of you.
You could have arguments over your differing viewpoints -- or you fight if they don't feel like obsessing about such issues all the time. You both feel compelled to do it, as if your time together would be wasted on mere small talk or superficial communication. This aspect could have a positive effect in the end, if it encourages transformation to a higher mental plane, or a higher level of self-awareness. The likelihood is more that your partner mentally tortures themselves due to your effect on them. They argue and obsess about things that never bothered them before, and they could experience bad dreams or a suppressed mood when they're awake. You might try hard to have control over their emotions and thoughts, which really pushes this relationship to its limits. You should try to give each other, and yourselves, a break from time to time, because this kind of influence can wear you both out if you're not careful.