Throughout its run, Buffy the Vampire Slayer got gradually more serious, charting a path for the Slayer that took her from unsuspecting schoolgirl to death-defying world saver, simultaneously transforming the series from a monster of the week format into a long-arced, much more adult drama.
But, even in the most serious of times, Buffy has always had room for a touch of humour, going so far as to often dedicate entire episodes to a spot of low-consequence fun, or just playing up the comic sensibilities of what was a varied and quite accomplished cast.
Magic has often been used to effectively insert some levity in standalone episodes that cut up the drama of the larger (and often awfully hard-hitting) storylines.
And it is magic that has most frequently guided the Scoobies into status quo-shifting situations that let them loosen up, go against type and play a different side of their character - or a different character altogether.
Willow has been a vampire, Giles has been a demon, Buffy has been Faith and Jonathan... well, he will always be our superstar.