How does the narrator's dialogue in Undertale contribute to the unsettling nature of the Genocide Route?

The narrator's dialogue in the Genocide Route becomes increasingly passive-aggressive and subtly encouraging of violence. They often comment on the player's actions with a detached amusement, subtly pushing them towards further destruction. This creates a sense of unease and questions the player's own morality, as the narrator seems to be both observing and influencing their descent into darkness.