What's worse than a crazy stalker ex? A crazy stalker ex who also happens to be a soulless maniac, bent on revenge because you gave him all the feels!
This is a super dark episode which shows that Buffy really was a show that wouldn't shy away from the darker side of the ideas it was exploring.
In the words of one of the Nerds: "B-Moms be chill". It's Buffy S02E17 - Passion.