I think this is something that doesn't want to be done, but just needs to be with no counter balance to it. It's like a bad breakup, just let her go as much as it sucks and know in the end it will be better than it is now. Scion just plain and simple needs to be gone, the cabal isn't working as it was intended.

People roll Scion more for the powers than for the role. Turn it into a religion if need be and have Mergulla be an appointment leader of it. I bet she will rarely have many followers based upon the beliefs and operating system of the cabal dogma.