Board Thread:General Discussion/@comment-26873653-20151212201934/@comment-679780-20151213024759

I think that Knuckles is still guardian of the Master Emerald, just sometimes he takes breaks.

I know it may sound really risky for him to just leave the emerald unguarded, but keep in mind only a few have the technology to actually invade Angel Island and the three most likely candidates are Sonic, GUN (Especially Team Dark) and Eggman.

However usually Knuckles part take in adventures when all likely canditates are involved in the adventure, so Angel Island will be relatively safe for awhile.

Think of it this way, while Knuckles seems to have built defences and traps for intruders, how long do you think Angel Island has been undisturbed before Sonic 3? It was considered no more than a myth before Sonic and Tails landed on the island.