Long ago two alicorns ruled over a mystical land where friends were always together both alicorns became embodiments of two elements, used to forge legendary lands love and friendship. Both alicorns became bitter and lost the ability to wield such elements, one being sent away outcast to live in darkness the other angry and filled with regret and hatred for the ponies she vowed once to protect thus throwing the land into darkness.
This is: the Brocken Alicorn.