7. The Fate Of Huey Emmerich
As well as one of the two men eventually responsible for the creation of Metal Gear, Huey Emmerich is a confirmed character to appear in MGSV and is also the father of a very important figure in the series - Ocaton. The Phantom Pain takes place in 1984 - four years after the birth of Otacon. From the events of Peace Walker, we know that Huey was directly responsible for the creation of the Peace Walker machines, and we know his research later went on to be used by others to create war machines of that caliber. What mysteries does Huey still have to reveal? Only time will tell.