When archeologist Jaclyn Hayes went on a trip to Tibet, her journey went horribly wrong when she died. Jaclyn's boyfriend Michael Taylor makes a deal with the devil and undergoes the unholiest of transformations into a demon in an effort to reunite with his lost true love. However, a group of monks saved her life, thinking that she was the fulfillment of an ancient prophecy and turned her into the Demonslayer. Her newfound destiny as "Demonslayer" makes them natural enemies.