As many of you know, in The Walking Dead Universe, no character is safe. Robert Kirkman himself has stated it many times. And while I think Carl Grimes is one of the most bad-ass comic book characters in the history of the world, I think he is in for some tough times, maybe even death. In one example, there was a man who got the book 'Rise Of The Governor' signed by Robert Kirkman. Robert wrote in his book, along with a signiture, 'Don't worry. I will NEVER kill Carl'. Then he slowly looked up and told the man "You know I am lying, right?" Also, as badass as Carl is, he is only a 9 year kid. He has already been shot through the chest, shot through the eyeball and mentally tortored with not only the death of his mother and sister, but many others as well. If some of your theories are correct, and Negan has put an iron to the side of Carls face, then I don't think Carl would be able to handle that kind of trauma. That said, I don't think that is how Negan will do it. My theory is that Negan is going to force Rick to kill his son himself...
Herschel Greene