Mortal Kombat vs. DC Universe
In this arcade fighting game, the DC and Mortal Kombat universes are represented by 10 champions and one "boss" character each, for a total of 22 fighters. The game is similar to the 2D Mortal Kombat games (with some 3D elements) and focuses more on the special moves aspect than the complex combos of the three previous games (Deadly Alliance, Deception, Armageddon). As in all Mortal Kombat games, there are fatalities for the combatants and villains, although somewhat toned down to conform to DC standards, according to which heroes like Superman and Batman stick to their moral code and don't kill their opponents. Therefore, the DC heroes perform "Heroic Brutalities" that effectively incapacitate their opponent.
Story
After Shao Kahn's invasion of Earthrealm is stopped by Raiden's forces of light, Raiden sends Kahn through a portal. At the exact same time, Superman on Earth stops Darkseid's apokoliptic invasion by shooting Darkseid into a boom tube with his heat vision. These acts don't destroy either of them, but merge them into Dark Kahn, merging the universes of DC and Mortal Kombat. In the process, the characters' abilities fluctuate and violent "rages" occur, which are actually Dark Kahn's emotions being instilled in the characters from afar. Since both worlds believe the other is responsible for the fusion, they fight each other until there is only one fighter left from each side.