I would suggest you have not answered your own question. Arguably, what you have achieved with vigor is the consequences to the answer.

To be precise, my experience over 30 years with a former narc wife distills down to one salient truth; the narcissistic personality disorder has no moral self. Their language and all communication is not of the world of the nuro typical individual. The filters they employ are without morality hence, never feeling shame or guilt. Without these realities the narc’s reactions to triggers will be precisely as you describe.

Futile is not in the nature of the outcome but in the improper expectation entering the exercise. Futile always begins at the outset. The rest is simply ordained according to the facts understood [or not] at the moment oneenters the exercise.

Thank you.