...I feel...cheated on.

Anyways all of this stuff can only help prove that the Fused shadows and Majora's Mask are from the same tribe. It's easy to explain how the two are similar, but there is very little proof to say they are parallel or of the same family. In my first thread I used the Happy Mask Salesman as proof against this. From the little info MM gives us the HMS (Happy Mask Salesman) wasn't from Termina. He was simply following Link and the Skullkid around. (The skullkid is also the one from OoT) And he was the one who found Majora's Mask again after it was sealed, but he never flippin' bothered to tell us where he found it Hyrule or Termina.

From my understanding there is no proof saying that the HMS found Majora's Mask in Termina. But rather since he's from Hyrule he probably found it there too. and stumbled into Termina the same way Link did.