Master Emerald

The Master Emerald is a massive, green Chaos Emerald that keeps Angel Island afloat. It was created by the combined might of Athair and the Brotherhood of Guardians,during a confrontation between Super Sonic, Hyper Knuckles, Turbo Tails and the recently empowered Mammoth Mogul. The Master Emerald contains the powers of the twelve individual Chaos Emeralds which formerly held Angel Island afloat.

Creation
When Mammoth Mogul stole the power of 11 Chaos Emeralds from the super being Enerjak, he transported Sonic the Hedgehog, Tails and Knuckles the Echidna to an alternate Zone. There, he fought the three in their super forms, while Athair distracted him, until the Brotherhood of Guardians used their combined knowledge and powers of the Chaos Force to trap Mogul within the newly created Master Emerald. It was then used to maintain the island's low orbit of the planet Mobius. (StH: #56, KtE: #9)