Who is the protagonist in the Circular of Ruins?

The protagonist of Borges's story is most clearly the dreamer who sets out to dream a man to life. If we define a protagonist as the character whose action drives the story forward, then he is our clear answer, even though perhaps this story does not function in so traditional a manner. At the end of the story, though, the main character has the insight that he too is a dream creation - that is, that another individual has dreamed him to life the way he dreamed his own creation to life. This happens in the last sentence. However, this realization does not make a strong argument that the main dreamer is not the protagonist.