Power Stone

The Power Stone is an object that appears in Sonic Underground. It is a large green jewel that sustains Mobodoon and allows the town to visit Mobius.

Description
The Power Stone is seemingly capable of magically generating the town of Mobodoon, as well as its environment, and as well energize them. It also allows the town of Mobodoon to visit Mobius from its home dimension once every four years, during a full moon on the second day of the third month. It also generates incredible amounts of powerful energies which can be harnessed from it.

Taking the jewel from its pillar will cause Mobodoon to fade from Mobius forever in a matter of hours; the skies will darken and gloom, plants will wither and the buildings will begin to crumble.

History
For at least fifteen years, the Power Stone has sustained Mobodoon. When Sonic, Sonia and Manic visited Mobodoon during its time on Mobius, Sleet and Dingo followed them there and invaded the town, where they wanted to collect the taxes Mobodoon owned Dr. Robotnik since its last visit. Because Mobodoon did not use money, Sleet got the SWATbots to collect anything of value, including the Power Stone, which caused Mobodoo to fade away. The Power Stone was then placed inside Sleet and Dingo's tanks and was transported away from Mobodoon, but Sonic, Sonia and Manic was able to stop the transports and use the Power Stone recharge their medallions, allowing them to drive off Sleet, Dingo and their forces. Sonic was then able to bring the Power Stone back to its pillar minutes before Mobodoon faded away forever.