Mephistopheles

“I let him run on, this papier-mâché Mephistopheles…” (Conrad 37).

The name Mephistopheles (also sometimes Mephistophilus or Mephisto) is a name used for the Devil, or Satan. (http://www.britannica.com/EBchecked/topic/375514/Mephistopheles)
The fact that he is described as “papier-mâché” means that he is insubstantial and deceptive, seeming more real than he is. This is one of many allusions to Europe and Europeans being fake and hollow.

(http://upload.wikimedia.org/wikipedia/commons/8/8f/Keppler-Conkling-Mephistopheles.jpg)