If you work in silence and smartly plan the case and prepare your evidence which is rock solid, you will be okay. Just remember, regardless of what the picture below states - Judges and Magistrates are not stupid either.
Narcs are incredible liars and actors, but the truth has a miraculous way of unravelling itself at the most splendid time.
When you are escaping the narcissist and it ends in a court case, my best advise is this. Hit them with everything you have got, be truthful and factual with as much detail and evidence as possible.
You can do this. You just keep doing what you are doing. I am not telling you it is going to be easy, I am just saying it is very possible.