The Call Of War by Kyle Levien

As the campaign of The First Great Rebellion drew close to the Blackwatch Keep, the Marquis of Skulls drew desperate, then reckless. As the forces of The Four Heroes surrounded Blackwatch Keep, the four Royal Mages were called to a meeting deep beneath the keep in foul crypts beneath the city. Decades before they had been sent forth to learn the infernal ways of their magic. In greasy, blackstone keeps they had learned Blood Magick, the Magicks of Smoke, Shadowmagic, and Magic of Ash. The Marquis of Skulls commanded they combine their wicked magic to commune with the infernal realm’s Queen of Hell. Using the magic of Blood, Shadow, Smoke, and Ash the Marquis made a pact with the Queen of Hell. A gate would be opened between our realm and their’s, demons would join the ranks of the Skull Soldiers to beat back the rebellion on the condition that once a portal between realms was open, it might never be closed.