the main character talks about layering up his clothing he then says "they were fashionable, and we had no idea that his unusual way of dressing was going to benefit us" what is he forshadowing?

In a way he is suggesting the protective power such layering might provide. Since he is a soldier, he will need all the protection he can get. Such layering might defend him from any kind of attack and save him from being killed. He is foreshadowing the attacks that may come in the later parts of the story.