>/sthg/ having the "They should Destroy the Master Emerald so Knuckles can be free to roam the world" talk AGAIN
As Heroes, Shadow, 06, Lost World, Forces, and Frontiers have shown us, you do not need the Master Emerald to be a part of the plot for Knuckles to participate
When the world is in trouble he comes down to help out. Simple as
>BUT
When his friends are in trouble he comes down to help out. Simple as
>NO THAT'S NOT FAIR YOU MUST
When he wants to take a break he comes down for a bit. Simple as