It is an artifact in the form of a medallion of vast and neublous cosmic power, watched over by a mysterious guardian somewhere in the Gateway to Limbo or thereabouts. wReamed Acton Lord and Netlurker stole it and implanted it in the Peril Room to trap the LNHers in Limbo. It was last seen in the hands of Those Annoying Crosspost Brothers.
It may be the same as the Siege Plot-Device which Occultism Kid mentioned in the Electrocutioner's Song. But perhaps it is not, for in the Omnilooniverse, all things are possible, especially silly things.