Joss Whedon's Buffy The Vampire Slayer is a supernatural teen drama with many mature themes for a show that aired in the late '90s. It follows a teenage girl who discovers she is the "chosen one" meant to kill vampires in the town of Sunnydale and keep the world safe. It is a challenging task to place on the shoulders of a teenager, and she ends up falling in love with one of the creatures she is supposed to kill, the vampire with a soul, Angelus. Angel and Buffy have a short yet intense romance after he experiences a moment of true happiness. He reverts to his menacing ways before he gets his soul, devastating Buffy and all the friends he'd made in Sunnydale.
Source：https://www.cbr.com/how-buffy-spike-relationship-set-stage-fantasy-love-triangles/
