Black Magic. book 1

Two sisters, Charlie and Destiny, are very close and love to adventure. One day on one of their adventures they come across a very rare Black Friesian Unicorn. Unfortunately, the unicorn did not appreciate being disturbed and cursed them with Black Magic. Now the girls have new evil powers that they must learn to control or everyone they love or come into contact with could be hurt or killed. Can the sisters ban together and find a way to cure the curse or will their powers tear them apart and throw the world into chaos and destruction?