I wonder now if this is supposed to be the Data Keeper from the game's ending. In the PC version, there was more than one and they were specifically aliens, but the NES version only confirms one and doesn't say what he is, so he could easily be a normal human in that version. That would explain all the books, scroll, and the feather pen. It's all speculation, but that may also explain why he was removed - someone may have wanted the nature of the Data Keeper to remain more ambiguous.