Guardian - Supernatural -
A born fighter, Sage Black is rescued and taught by a Hunter, who shows her the creatures in the dark. Becoming a Hunter herself, Sage and her friend Ollie; the only monster she's ever spared, travel together hunting and saving people. Sage discovers a forgotten past, with the help of Ollie and the famous Winchesters, and the eye opening angel named Castiel.
Supernatural fanfic. Will contain spoilers. Castiel and Sage are the ship on here.
**IF YOU DO NOT LIKE GAY THING (why are you here) OH WELL** contains hints of Destiel, smut, Sabriel, more smut and fluff. Oh and gore. So Supernatural at norm.