Not all kids are exposed to such things and what's wrong with not wanting to show them the kill cams and what not. I would not let my 13 year-old play skyrim. It is for advlts
If you think about it, the only thing that is for advlts is all the logical explanations of the game. The backmasking or hidden sixual references are already hidden to a point where most people of the age of 15 wouldn't get, let alone a 13 year old would understand it.
Anyway, you want your kid to learn at an early age, it will give him confidence and skills on how to learn on his/her own. That's why 'helicopter parenting' is so dysfunctional.
Let's be realistic here, video games is not a source of evil. Most kids by the age of even 12 know most curse words and sixual words, and have been exposed to a lot of as you call it 'advlt' aspects of life. It's part of growing up, let him discover things on his own so he won't become dependent of everything.