Amulet of Shinnok
The Amulet of Shinnok was among the most potent of mystic talisman within the realms. Millenia ago, Shinnok concentrated his power within it, in a bid to control the realms. He was only narrowly thwarted by Raiden.
It would thereafter continue to be play a major role in the various Mortal Kombats and struggles for the realms; most notably, during the events of Mortal Kombat 4, when Shinnok would rise from the Netherealm in another bid for total conquest..
Before the events of Deception when Shujinko gathers all the 6 Kamidogu and placed them on an altar to the Elder Gods within the Nexus, then suddenly Onaga the Dragon King of Outworld upon his return from the dead reveals to Shujinko that he had not gathered all of them. And the seventh and final kamidogu left turn out to be Shinnok's amulet in the hands of the sorcerer Quan Chi before he arrrives in his homeworld to reclaim his kingdom and obtain the amulet to begin reshaping reality itself in his own image.
What has become of the Amulet of Shinnok and the danger it poises remains uncertain.