Nobody tell them about Mortal Kombat.
"Oh, but that's different."
How? Everything in Mortal Kombat is 10 times worse than the violence and gore in this game; but it's ok in Mortal Kombat because Subzero doesn't have intercourse with Kitana before ripping the spine and skull from her body before wielding it like a mace and beating her with it? Would it only cross the line if Sheeva sucked Johnny Cage's dick before she ripped all the skin from his body in two clean pieces? Would it only become inappropriate if Goro got a handjob from Scarlet before he ripped her arms off and beat her with them? Sure, it's totally fine for Mileena to rip Jax's head off his shoulders and literally eat his face, but only if she doesn't let him hit it from the back first.
What's "unnatural" is an adult with the inability to separate fiction from reality. People are so quick to pearl clutch about gore in H games because "Oh my goodness! It's ONLY the blood and violence gets these sickos aroused, definitely NOT the sex stuff! Committing acts of wanton violence and destruction is the only way for these people to get a nut off! What if the games stop being enough for them and they step it up to doing it in real life and murder their sexual partners?!"
I'm here to tell you that 99% (excluding the 1% of genuine psychos that were already psychos before these games existed) of people who play these games, yes including Mortal Kombat, are perfectly sane adults who are capable of separating fact from fiction. It's like saying that someone who plays Call of Duty is one step away from going completely fucking postal and gunning people down in real life. There is no connection. You're living in the scary nightmare land of "but WHAT IF?!"