[quote=@Mythos]
So according to the laws, the killing of a purebred is met with death, but feeding from vampire blood is also met with death. 

What happens with a feral Purebred?
[/quote]

If a purebred is a feral vamp, they are basically forfeiting their protections from being a purebred. A purebred feral is treated the same as any old feral.