Sources familiar with the matter say Angelina has been out for blood. As one source connected to Brad tells us, they believe she wants to kill any relationship he has with his kids. We're told there has been a lot of screaming on Angie's part ... as one source said, "She's fueled with anger and has gotten ridiculously unreasonable."

Our sources say her lawyer, Laura Wasser, is going to quit and made that known to her, because it's gotten too venomous. It seems like this was not a good match, because Wasser has made a name for herself in divorce circles by promoting settlements and co-parenting.

We're told Angelina has hired another law firm to take over when Wasser officially leaves, but for now the divorce is nowhere near settling ... it's more like all-out war.