Dark Khan

Dark Khan is the boss of Mortal Kombat vs. DC Universe. Not much is known about him other then he is the outcome of Shao Khan and Darkseid's accidental fusion. It is thought that Dark Khan has a large part to do with Rage Mode due to his appearence in the Kollectors Edition Komic when a character goes into rage mode (e.g. He is seen with an evil look on the Captain Marvel vs. Raiden page).

Creation
Dark Khan was created when both Shao Khan and Darkseid were being defeated in the same space of their seperate worlds. Due to the immense force used to defeat them and their own power being leaked as they were defeated, a black hole was created causing a rip in the fabrics of their seperate wolrds, causing both Shao Khan and Darkseid to merge together along with the Mortal Kombat and DC Universe worlds.