You could write a story about the life of a witcher from the Mikaelson, Petrova or Salvatore family who became the Scarlet Warlock or the Phoenix Warlock, having the powers that Jean Gray has as Dark Phoenix

Could write a story about a Mikaelson witcher

you could do a story about a witcher from the Salvatore family. And get him to date Elijah.
          
           Or a wolf-witcher hybrid. Being half witcher from the LaRue Family of New Orleans and half Alpha Werewolf from the original Deep-Water Werewolf bloodline. Doing so is the Alpha of the Appalachian Mountain Wolf Pack. And for him to date Kol.
          
            Or it could be a witcher with powers similar to Marvel's Doctor Strange. But this witcher would be a member of the Deveraux family of New Orleans. And for him to date Finn.
          
            Or it could be a witcher descended directly from Cage's bloodline. This witcher could belong to the Sinclair  bloodline of New Orleans. This witcher could date Marcel.
          
           It could also be an elemental witcher of the Griffith bloodline of New Orleans and he could practice a unique form of magic. This witcher could date Mikael.