Shan is considered to be a first person narrator because he both tells the story and appears in it. A first-person narrator would obviously use the first person pronoun (I) to refer to him/herself. So, the entire story is told from this person's point of view, using that particular pronoun. E.g. 'I saw him standing there...' is an example of a first person narration which Shan is an example of. If he were talking about someone else, it would be third-person narration.
An anticlimax is a disappointing (or unsatifying) ending to an otherwise exciting series of events. Example: think of an action movie that just ends without wrapping up the loose ends or leaves too many unanswered questions.
