To unlock this achievement, you need to unlock every Iron Man armor that can be selected when pressing and holding
as Tony Stark (or any Iron Man variant), and then use them all in one session. I say this because Mark 38 (Igor) is listed as a separate character and does
not count towards this achievement (the DLC armor also does not count towards this achievement). Don't be like me and think you need Mark 38 before you attempt the achievement. Below is a list of all 14 variants and where to get them:
Iron Man (MK1) Malibu Hub - Hall of Armor.
Iron Man (MK5) Malibu Hub - Garage.
Iron Man (MK6) Complete Story Level 4: Shakespeare in the Park.
Iron Man (MK7) Complete Story Level 6: Avengers Assemble.
Iron Man (MK16) Story Level 11: No Strings On Me - Part C (surrounded by fire on left side of room).
Iron Man (MK17 / Heartbreaker) Malibu Hub - Living Room.
Iron Man (MK25) Manhattan Hub - Helicarrier Laboratory.
Iron Man (MK33 / Silver Centurion) Manhattan Hub - Central Park (Agent Coulson mission just outside of the park).
Iron Man (MK40) Manhattan Hub - West Harlem (Agent Coulson mission).
Iron Man (MK42) Complete Story Level 9: Ready, A.I.M., Fire.
Iron Man (MK43) Complete Story Level 1: Struck Off The List.
Iron Man (MK45) Complete Story Level 15: Ultron Undone.
Hulkbuster Complete Story Level 12: Anger Management.
Superior Iron Man Manhattan Hub - Avengers Facility (underneath black cosmic brick circular panel).