Joss Whedons Buffy the Vampire Slayerdoesnt have casual fans. Theyre obsessed creatures with a rabid bloodlust for all things Buffy, be it comic books, action figures or fiction penned by fellow devotees and posted online. So if you arent a Scooby-lovin psycho, we suggest extreme caution when attending tonights showing of Buffys musical episode at the Screenland Granada (1015 Minnesota Avenue in Kansas City, Kansas). Borrowing from Bertolt Brecht, Rent and Cole Porter, Once More, With Feeling finds the denizens of Sunnydale singing and dancing their true feelings. Ex-vengeance demon Anya sings about marrying good guy Xander, good witches Willow and Tara sing about being lovahs, and evil-hot Spike shares a naughty kiss with the slayer. Its a drama-club geeks wet dream. Tonights and tomorrows showings are at 10. The $12 admission includes a Rocky Horror-like goody bag. Purchase tickets online at screenland.com or call 913-621-1800.