Everypony knew of the story of King Sombra and his reign over the Crystal Empire. Few knew, however, of his firstborn son - the mighty Warrior-Prince Ostrath, a Demon Alicorn - half-unicorn, half-changeling - that lived on thanks to the kindness of his changeling mother and the guidance of an old earth pony. His journey takes him all around Equestria in search of fragments of his broken horn, scattered because, were they to be brought together back on his forehead, they would force the darkness and changeling blood in him to overcome his entire body, turning the Prince into a dangerous weapon that could bring all of Equestria to its knees. On his long quest, he meets the commander of the Equestrian Army, falls in love with Princess Luna, meets an entrapped Discord, and faces off against the shadowy spirit of his father.

May contain swearing at some points. There's also much violence involved.