Unseen character (not a ghost character, someone who doesnt speak in plays) are causal figures included in dramatic works but are seen as more powerful because they are only known by inference.
An unseen character in theatre, comics, film, or television, or silent character in radio or literature, is a character that is mentioned but not directly known to the audience, but who advances the action of the plot in a significant way, and whose absence enhances their effect on the plot. It is a character who is mentioned as appearing on stage, but who does not do anything, and who seems to have no purpose. 
