Buffy the Vampire Slayer (1997)

S7E21 End of Days

Buffy discovers a potent new weapon in the form of an enigmatic scythe, but her friends are unable to uncover its origins. Determined to learn more, she embarks on a quest for knowledge on her own. Along the way, she encounters a familiar ally, rekindling an old friendship, while also facing significant peril that threatens them all.