DarkHeart was a rather unique unicorn, seeing as he was born with the ability to be able to control dark magic, which caused him to be feared by everypony that he had ever met. With his talents driving everypony away from him, he was left without a friend in the world-even his own family ran him out of their life's'-But that was only the beginning of his troubles as he would soon come to find in his later years of life.
He'll have to face many challenges that will test him physically, mentally, and emotionally without assistance from any of his friends or family (like he really cared). Though he doesn't understand one of his challenges when it tells him to find the spirit of friendship.
( Won't get to the gory parts until somewhere after the third chapter maybe sooner, but won't be sure until I get to it and is set before the show even begins, go to somewhere in the middle of the second season, goes on from there.)