Nathan Fillion (news) is joining the cast of “Buffy the Vampire Slayer (news – Y! TV),” taking on a key role in the final five episodes of the about-to-wrap series. Fillion, who most recently starred in “Buffy” creator Joss Whedon’s short-lived Fox television drama “Firefly,” will play Caleb, a man of God who’s… Well, all … Continue reading Captain Tightpants on Buffy?