In this case I’m assuming the target, who happens have strongly a narcissist traits, doesn’t consciously know that someone has cursed them (or done whatever magick on them) - no matter what the magick, there’s a noticeable trend that people who are obviously narcissistic are difficult to curse - based on the numerous posts we have on here about it. Anyone can hexbreak a curse if you know it exists.
There was also a good point here:
A typical example is this experienced member who made multiple attempts, not just for revenge but to stop his attacks on her: Curse for narcissistic guy at work