The First Slayer is a significant figure in the lore of the Buffy the Vampire Slayer universe. She is the original vampire slayer, chosen to combat the forces of darkness. Her existence is tied to the mystical powers of the Slayer line, which grants strength and abilities to those who follow in her footsteps. In the series, the First Slayer is depicted as a primal warrior, embodying the raw power of the slayer spirit. She represents the origins of the slayer legacy, and her influence can be seen in the struggles faced by later slayers, including Buffy Summers. Her character explores themes of destiny, sacrifice, and the burden of power.