S14, Sam months of not eating, sleeping and not taking care of himself in general catches up with him in a really spectacular way. I would love for him to get sick with something really serious like organ failure or catches something really bad because he has zero immune system. Dean has seen it come it and has tried to prevent it but couldn't succeed. Jack on the other hand, has to face with the fact that not only he is human, but who he sees as his invincible, always there for him, father, is too.