Still soaring around the now devastated Sentinel Island, I stumbled upon a grave with a letter in it. It was simply signed "-M". I won't give away its exact location, however, it's close to where you exit the tower.
This probably isn't the best place to be posting a topic like this (not exactly a much needed hint or trick), however, due to it's semi-hidden nature, I think it might interest some people and raise a few questions.
-Merdarion
