Linking is appropriate for when the first time a character's name appears in an article (as it has been done in the past.) This really makes the article look sharp, and not blue all over. Re-link if you go into a different section of the article, or if the article has many senction, but re-link only once per section. Don't link the name of the article to the article itself. For example, don't link Rebakah Cooper to Rebakah Cooper as the reader would already be on that page, and would honestly just be confused.