Board Thread:Speculation, Theories, and Rumors/@comment-34518800-20150509005546/@comment-1784865-20150519011325

Myself 123 wrote:

Uxiea wrote: If there was, the rivalry and contrasting dynamic between the Metal and organic Shadow would be nowhere as interesting as Sonic and Metal Sonic's. The idea's done so I don't see the necessity for a Metal Shadow anytime soon. I think you've hit the nail on the head there. That's probably the reason why we haven't seen Metal Knuckles or the Tails Doll since Sonic R. Precisely. They were only filler characters and didn't have a point probably other than to add "anti" versions of the main 3 characters.