Revenge!

Willow wants to get back at the woman who raped her 'brother of the heart'- Xander Harris. Even though Willow and Xander aren't related in almost any way- she actually sees him as her brother; so she is very protective of him,,, and vendictive towards anybody who hurts him- like Faith did in "Consequences", Willow and Kennedy gang up on Faith and enslave her! P 1 'sister's betrayal