Slayer

In the Buffy the Vampire Slayer continuum, a Slayer is one woman (usually called as a teenager) who fights magical evil in the world. A Slayer has augmented strength, agility, and healing compared to normal humans.

When a Slayer dies, another girl is called and receives the powers of the Slayer.

In BtVS fanfiction, Sues will often become Slayers.