Edgy pone  
He is a Kirin with the ability to read into the future of relationships. Despite this, he can only see the negative aspects of it, and when he informs a couple of their future, he essentially “crushes their hearts” and gives them the choice to break up immediately or continue on, where eventually his future reading will take place and they’ll break up in a more tragic way, hence the dark arrow splitting the heart cutie mark! If he can’t see a negative aspect of a relationship, he’ll simply tell the couple that they have met their special somepony.