what I know so far is the following. I tried to reverse engineer the backstab from Dark Messiah by decompiling models. I found that in the QC files they had the backstab animation fire on an AE_EVENT which is referenced in the npc .cpp. My guess is that in the code, whenever you fulfill the conditions (close enough, they can't see you, etc.) you are able to backstab, which positions (although in game it blended) the npc's backstab animation global origin to the player global origin and plays it, where after finishing the npc turns into a ragdoll. Now it all sounds very easy in words, and if there existed a coding language where I could simply use written english text and the compiler would make sense of it, I'd probably be able to achieve this effect in no time. But since I have only a VERY basic understanding of C++ I can't get even close to realizing it. I want to learn it really bad though, but I have no clue where to start learning. I found a couple of video tutorials, but they are very basic and I don't understand how general C++ tutorials can help relate to Source code because it is so much different. (to me at least)
It'd be interesting to decompile the Zeno Clash models and see whether they were using the same technique.
OK, that was a massive derail, let's get back on topic now.
Microsoft is fucking anal about getting money, I'm surprised that they didn't crucify Gabe Newell as payment for free DLC D: