Strong emphasis on Buffy's ambition to become a better, tougher, stronger, more powerful slayer.
More cool training sessions with Giles, more scenes with Buffy doing general research and research into the slayer history, more meditating and a greater interest in magic, not just trance states, I'm talking actual offensive stuff, fireballs, sunlight spells and shit, I mean, Buffy was already doing advanced trance spells on her own and Willow was researching a sunlight spell for her why didn't they do anything with that anyway? Think about it, Witch/Slayer multiclass, how an awesomely overpowered combo, I can stake you or set you on fire, pick your poison undead maggot! And whenever Buffy's hurt, she pours her pain and her anger into her quest for becoming stronger. My boyfriend left me? **** it, if he'd love me he wouldn't have left, right, and I don't need a guy right now. I'm gonna do some extra training, hang out with my best buds, dance some with Xander and by the way that new vibrator is pretty wow. Mom died...OK, grieve, wallow but the stress and the anger? I'll blow off that steam with slaying. Yeah, shit like that you know. And speaking of anger? More righteous, slayer anger outbursts like in "Into the Woods". No mercy for suckers, with stake and fire, send the bastards into hell like the hell of a woman you are. Death is your gift? Well, embrace your inner Kali and keep on spreading that charity like a horn of plenty.
So, it's time for the final battle. Buffy makes use of her newly acquired magical-foo and her newly acquired god hammer and hammers Glory to dirt. She saves Dawn, Scoobies, in glory, walk away into the rising sun. There's a smile on Buffy's face because finally she understands that it's not about power and that it's not even about slaying, it's about protecting. Finally, she knows what she is, THE SLAYER and for the first time in her life she truly ****ing loves it.
Yeah, the best season ever.