The Black Master

You are correct, Agent T, the basics of the hero we come to know are present in this very early representation of The Shadow.  Here is the review of one of the great early cases of the original Dark Knight.  Read this novel if for no other reason than to read these lines "The secret of The Shadow," came the monotonous voice. "At last it is understood! The man of many faces - with no face of his own!"

Just for fun...