Taken from Official Collectors Guide
To obtain the codename hero you must have completed main mission
and reached a total of
heroism points. The achievement will unlock immediately.
Just a reminder that you can get more heroism points from doing the same main mission over again.
*an upgraded helicopter with armor helps a lot
Mission 33 can be completed in roughly a minute if you use the helicopter and deploy right into the outpost. Simply destroy the 3 satellite dishes with the mounted machine gun. You will receive a S rank and 1580 heroism points.