The theme of ‘Slayer power’ is explored deeply in the episode Ted. Buffy feels that there is something wrong with Ted, but we’re never sure whether this is down to her Slayer intuition or whether she’s just jealous of Ted’s relationship with her mother. A similar theme is explored in season four’s Living Conditions when Buffy accuses her annoying roommate of being a demon, though, in fairness, she eventually turns out to be right! It’s an interesting conundrum for her friends - is Buffy simply using her Slayerness/Spidey-sense (see below) as an excuse for her personal dislikes, or does she really feel that something is wrong?
Another of the episode’s important developments is Buffy’s realisation of her strength, and how to use it. She accidentally kills Ted and is instantly horrified by her actions. She realises that she wasn’t chosen to kill humans, no matter how bad they are, or may seem to be. This is something which Buffy strongly believes in throughout the series. In Bad Girls, Faith accidentally kills a man and the differences between her reaction and Buffy’s are marked. Buffy, and possibly more noticeably its spin-off Angel, also explores how power shouldn’t be used indiscriminately when it comes to demons. Buffy realises that there are many different types of demons, and they’re not all evil so she shows mercy to helpless or harmless demons. For a different slant check out Riley’s reaction to this ‘multi-culturalism’ in New Moon Rising. Of course Joss was in no way influenced by Stan Lee’s famous Spider-Man motto: “With great power comes great responsibility”.