Edward and Roy
Officially, Colonel Roy Mustang is Edward's superior officer, but their relationship is far from the typical professional connection. There exists between them a sort of amicable animosity, as Roy takes a great deal of personal pleasure in teasing Edward and watching him squirm under his orders and, at the same time, Ed takes pleasure in getting around his orders and showing Mustang up whenever he manages to find an opportunity. Though their meetings are fraught with a great deal of apparent, mutual dislike, Mustang and Edward hold a great deal of respect for one another and are compatriots as well as co-conspirators in the secret battle against the homunculi. Having originally scouted the young boy for the State Alchemist program and formed a bond with him, Roy genuinely wishes to see Edward fulfill his goal and Edward also subtly supports Mustang's secret bid to become the Führer and improve the country.