I'm sorry to hear about Ally. It reminded me of a cat that was adopted from our adoption center. She was so vicious I was afraid of her and we used leather gloves to return her to her cage.

A saint adopted her, took her to the vet, and found out that she had numerous infected teeth. The first vet didn't "notice" the severe dental problem. Once her teeth were taken care of, she calmed down.

My point is that her rage could possibly be the result of internal pain. Is it possible you could go for a second opinion?