It absolutely is justice for his kids' future. No doubt, this is going to be hard on them, but his kids now have a better chance to be normal since they will not be exposed to the mental torture and the physical danger that their mother put them through since the separation.
Therein lies the problem. She has refused to get help for 12 years, which is why he finally left. She's not the type you can force to do something she doesn't want to do. Hopefully all of this forces her to get the help she needs.
That's a heck of a story, codell, and I wish them all well, even the former wife. Hopefully, she will finally get some medical attention that will at least moderate her symptoms. This should be the wakeup call she needed to convince her to get help. It's not at all unusual, IMO, for people with mental health issues to deny their existence. A breakthrough might come from finally taking that step, and maybe this terrible experience will be the push she needs. There are some remarkable medications out there now. I hope she gives herself a chance. You did your friend, and his kids, a solid by standing up for him. That's what friends are for, of course, but not everyone would have wanted to go that extra mile, especially considering the apparent mental state of this woman. I assume that she heard your testimony. Perhaps everyone will be lucky and she'll maintain a modicum of normality.
I have a friend who went through a similar situation. His wife started having anxiety, depression and other mental issues. She started self medicating, lying and was in a downward spiral to the point where she couldn't walk or eat. I honestly feared for her life. He made some tough love choices and to her credit she put in the work to get clean and get help. It's been almost a year now and I hope things continue to go well for them. Here's hoping for the best for all parties involved in these types of situations.