Buffy the Vampire Slayer
The Slayer or Chosen One is a girl who kills vampires. She had superhuman strength and speed. She also heals very fast. It is her destiny to fight evil demons, mainly vampires. When the Slayer dies, a new girl is chosen. That girl gets all of the powers of the Slayer. Potentials (girls who might be chosen - "potential slayers") are trained from an early age by a "Watcher". In this series, Buffy Summers, Kendra Young, and Faith Lehane were the main slayers.