SO sorry about your brother... That leaves scars on humans as well, I can imagine it would also scar his dog's psyche, poor thing. So sorry for your family, that is so hard to deal with.
I actually raised a puppy from 4 weeks, but I did have a stable female at the time, and she took on the maternal role. He slept with me, however, curled up between my neck and my shoulder, and he would stare into my face, imprinting as an infant does. More than any other dog I have had, as he grew he seemed to actually try to imitate speech, and use his paws as 'hands.' He was special.