Guardian Stone

The Guardian Stone is a mystical gem located in North's Workshop.

Lore
The Guardian Stone is only used when the Man in the Moon is choosing a new guardian. The gem used the Man in the Moon's moonlight to refract the light and created a spectrum of the new Guardian.

The Guardians were supersized to see the stone and were exited to know who will be the newest member: the member that can help them to stop Pitch Black. Bunnymund wasn't happy of the idea of Jack Frost becoming a Guardian as the stone showed an image of the trouble making Winter Spirit, but North trusts believes in MiM's choice and he knew that MiM wouldn't of chosen Jack if he didn't think or believe that he could help them.