What is Shinnok?
1.
In the mythos of Mortal Kombat, the fallen elder god who, a couple million years ago, attempted to take over the realm of Earth, fought a war with the thunder god Raiden, lost, and was condemned to the Netherealm (Hell) for all eternity. In 1997, with the help of the sorcerer Quan Chi, Shinnok finally managed to escape from his confines after trying to escape for millions of years. From here he sneaks into Edenia and launches a war against the elder gods. This was the plot of Mortal Kombat 4. At the end of MK4 he was killed by Liu Kang.
Note: Quan Chi's ending depicts him killing Shinnok during an argument, but that ending is not considered official because it implies that the bad guys won, which they did not. However, the fact that Quan Chi had the real amulet is official.