Hey donnamp; something about your command of the details here makes me suspect you're involved with the guy, so my unsolicited advice would be to beware. Feel free to let me have it if I"m wrong, but even if you're not actually involved, you seem to be serving as the counselor for this guy. He better be a pretty good friend, to be worth all the drama he's throwing your way on this one.
He's got a prenup and a vasectomy, custody of their kids, and a ton of evidence against her, if half of this is true, so I don't see how she can manipulate him from this point without his consent. Can he not afford an apartment for the rest of the divorce? Even here in Dallas, efficiencies can be had for $450-500 a month. Could the military send him somewhere else or provide him cheap housing for awhile? Has he cancelled the joint accounts and frozen his credit reports so she can't get more credit? (Most states allow that, btw for a $10 fee per bureau, unfortunately, I've got experience, there- ID theif opened up 10 accounts in my name a few years back).
Most people are on their best behavior for dating, but few sprout horns and a tail the day after marriage. Maybe guys are attracted to manipulative women for the excitement, or maybe as an excuse for lack of intimacy, or for lackluster life choices, or low self-esteem, or sympathy from others or to look better by comparison. Or maybe all these things, who knows. Same reasons so many women go for the toxic type. Some guys' cliche is to make it all out to be someone else's fault. Probably she is awful, but he sounds fairly complict to me. Good luck with it all, in any event!