Stop for a moment! Instead of seeing exes as narcissists, we can see them as someone who is so emotionally triggered that they’re entering fight or flight’ mode every time that something relating to your divorce is being discussed. A person in fight or flight mode can’t behave rationally even if they wanted to!
Just like you, they’re experiencing rejection, they’ve lost the secure connection they had (with you) and they’re not feeling understood.
It took me 12 years to learn this after my divorce, so I hope that hearing it now will save you years of heartache. Focus less on what they do and more on how you’re responding emotionally to what they’re doing. Insist on getting your demands met when they your demands protect your child, and do your best to do this without getting drawn into drama of the other parent. Focus on the drama that is going on inside your mind and remember that human beings react strongly when our own rejected character traits are mirrored back at us. If you’re upset by her lying, that’s a sign that you have some work of your own to do around honesty. Same goes for her craziness, her greed, her you-name-it. Your child needs you to evolve more than anything in the world and your ex is providing the unwelcome gift of a mirror.