When considering the Obstacle Character’s Throughline, look at their identity in terms of their impact on others, particularly the Main Character. Think of the Obstacle Character in terms of his name, but it’s the name of someone else, someone who can really get under your skin. In viewing the Obstacle Character this way, it is easier to identify the kind of impact that he has on others. Obi Wan Kenobi’s fanaticism (regarding using the force) in Star Wars and Deputy Marshal Sam Gerard’s tenacity (in out-thinking his prey) in The Fugitive are aspects of these Obstacle Characters that are inherent to their nature and would continue to be so in any story they might be found in.
From the Dramatica Theory Book