So so sorry. Your poor babies. That is awful.
I would push very hard for the guardian. Question. Could the T hotline him to DCFS? Just a thought as it is very clear abuse. My sister and her husband went through a bitter custody dispute as his children's mother is bipolar and abusive, also living with abusive men. The Guardian saw through all the BS she was telling the judge and her attorney. It was super helpful in their case. That's my only experience in dealing with that.
When I told my girls the truth about their father, that he has a mental illness and is a substance abuser to self medicate for that problem, I think it helped them both immensely. Through my dealings with my kids and the help of the T they are quite open and honest with me about it and this has helped me safeguard them.
My heart just hurts for you and your children. What an awful thing to have to deal with. Maybe he will go to jail soon so you don't have to deal with him. I would think so with the behavior out of control as it is.
Tight Tight Hugs my friend!