Before 'The Rookie,' Nathan Fillion delivered a chilling performance as the sadistic sociopath Caleb in 'Buffy the Vampire Slayer.'

Ryan Kiera Armstrong has joined the cast of the new Buffy the Vampire Slayer reboot opposite original star Sarah Michelle Gellar. The 15-year-old star, best known for roles in the film Firestarter and Star Wars series Skeleton Crew,

Into every generation a new Slayer is born, and now we know who the next Slayer will be. Reported by Deadline, Sarah Michelle Gellar will be joined in the "Buffy the Vampire Slayer" sequel series by Ryan Kiera Armstrong.