Yes, I discovered way back that presenting what I thought of as a glass or steel wall, with no chinks, was the best way of dealing with him. Well meaning friends, who had known and liked the person he was [and he underwent a HUGE personality change with ML] persuaded me at various times to be sympathetic and engaged with him. It never ever worked, and now I know why it never would have.
I am usually kind and generous because that is how I want to be, but I have no expectation that this will be reciprocated. But I no longer give him an inch, and I do not communicate other than when there is absolutely no alternative. Not to be pouty, but because I cannot give him a way in. I haven't seen him in nearly two years, although he said 'he wouldn't mind' if I joined him and our adult children for a lunch he gave them just after Christmas. His relationship with them is disastrous, but again they have realised that minimum contact is safest.
I just thought there is no way I am sitting down and playing happy families with this lunatic.
I knew he would delay over the money exchanges and make problems. I have a clear strategy which I will unfold in my own time, and achieve what I need to. There is only one way to deal with this behaviour, and it is contrary to what we want instinctively to do. Firm and absolutely detached, as if they were an exceptionally difficult stranger.
Knowing what is driving this insantiy helps to formulate our responses. Everything will be turned into a power struggle. It is interesting to see how many of these people go ballistic when we get our own lawyer and fight for what is due to us. And it is a fight. The financial deal that my XH proposed to me after a very long marriage was insulting. Yes, I spent a LOT of money on a lawyer, but I ended up so much better off.