Faith shook her head and was about to retaliate when Buffy came after her. The shock of it all made her miss blocking the first few blows and they hurt. She wasn't fighting like Buffy any more, no control or technique. She was fighting.. more like Faith actually.
So Faith fought back, slamming punches and kicks back with equal force. She wasn't even that concerned with blocking Buffy's blows, more letting them land so she could get an opening to hit the other Slayer back. She was even pretty sure she felt one of her ribs snap as pain flared through her side. Still, her (sore) jaw set grimly as she kept up the fight, inwardly wondering which one of them would end up unconscious first.