Neutral Mask meaning a bland, empty character for which the audience to place themselves upon in order to experience the show or movie through their eyes, as termed in this Cracked video:
Think about it, all the interesting Riders, 2nd Riders. Or in Drive's case, the third Rider. Although, Chase shows up before Go and is more interesting than him, so maybe Chase is the second Rider retroactively.
What do you think?