In order to unlock this achievement, the player must play a predetermined amount of time using Ms. Fortune with her head dismembered from her body.
To manually remove Ms. Fortune's head, use the Cat Strike ability (When facing right, press Down, Down-Back, Back + X) and continue to play. The achievement will unlock once the required amount of time has been fulfilled.
To expedite the achievement, play in VS mode, with the sparring option on, remove head and check back periodically until it unlocks.