I don't know enough about the reactions of the sexually abused to predict their future behaviour. All I can say is that, in relating to women, the sexual abuse is likely to take precedence over the NPD, if, indeed, it is present. It really depends on the nature of the relationship between the narcissist and the deceased. If the deceased was a major source of narcissistic supply - the result will be a major narcissistic injury. Such injury often leads to sudden, agonizingly illuminating, self-awareness followed by a quest to alleviate the excruciating, life threatening, pain.
Suicidal ideation is followed by panic.
This set of reactions is also observed following a divorce. If the deceased was a minor source of supply or not at all - the narcissist is likely not to react to the unfortunate event and to go on with his routine, to pursue his sources of NS, his petty squabbles, etc. This time - to himself.