“ Mortal Kombat II ” opens with an ultraviolent duel — the movie is one fight scene after another after another — in which Shang Tsung (Chin Han), the Outworld sorcerer who’s like a warrior from ancient times, faces off against Shao Kahn (Martyn Ford), who looks like the Lord Humungus meets Darth Vader under a helmet that’s a horned metal skull. (He wields a spiked version of Thor’s hammer, swinging it like an executioner’s ax.) Shao Kahn will be the film’s reigning badass monster, who tries to defeat 10 warriors from Earthrealm, all so that he can claim dominion over the other realms. That opening fight is stately and somber, even as it culminates in Shang Tsung getting his fingers lopped off — a preview of all the blood-spurting carnage the movie has in store for us. (That’s the gory icing on the action cake.) Shao Kahn’s reward for his victory is taking Kitana (Sophia Xu), Shang Tsung’s young daughter, and raising her as his own.…