Gemp,
I am sorry to hear about this. I have been through some terrible dog fights too. They are very scary and dangerous, and once it starts it just seems to esculate. And with the degree of fights your two are having, I also think you are doing the right thing. I hope it works out and you find a rescue for Voodoo, but if not...... I still think you are doing the right thing. I support your decision 100%!!
You gave Voodoo a home when he had none, you have done everything you can for him, but sometimes things just don't work out the way we wish them to.
You, Zeus, and Voodoo will be in my thoughts, and I wish you all the best.