Board Thread:General Discussion/@comment-32055665-20170610165552/@comment-35642588-20190223235701

Master Emerald did show up in a couple games after Advance 3, but it's all spin-offs like Rivals or Runners.

Adding onto the chaos emerald inconsistency, in the first game there wasn't even seven emeralds, there were six. In one game, Sonic the Fighters iirc, there was eight. And I'm pretty sure the first few games disagreed on everything about the emeralds down to the shapes.

Anyway unless there's a full-fledged reboot like the Genesis Wave in the comics, Sonic Canon will probably stay forever, a complete and utter mess.