A well-written fictional character has enough internal consistency that you can derive their astrological chart from the evidence in the text. The chart does not precede the character. The character precedes the chart. When written with real attention to how people actually work, the chart emerges naturally from who they are.
Not a game. Or rather, it is a game. Also a form of close reading.
The process starts with demonstrated behaviors, patterns, and blind spots. Not what they say about themselves. What they actually do across a season, a series, a film. From that evidence, you make the case for placements more consistent with who this character is than the alternatives.
Astrology through characters readers already know becomes very specific. Six seasons of a show, a character understood deeply: the vocabulary is suddenly not abstract. When the analysis lands, readers often describe their existing knowledge of the character reorganized into a more precise framework.
Because the character is fictional, the author cannot be accused of projecting. The evidence is in the text. The case for Carmela Soprano as a Capricorn rising with Venus in Libra is either based on specific scenes or it is not. The reader can check.
Some characters present harder analytical problems than others. Skyler White's chart cannot be built the way you would build Carrie Bradshaw's — the show's relationship to Skyler is less stable, the evidence more contested, and different viewers watched a different person. Where the evidence is ambiguous, the article says so. The ambiguity becomes part of the analysis rather than a gap in it. These readings are willing to say "this is a strong case" for some placements and "this is contested, here is why" for others.
Not prophecy. What is already there.