My rank right now is Legend, so I can't remember for sure when I got it, but I think you have to be a commander.
Inheritor, the last rank in the game. The last helmet, the Haunted Helmet, is the Pilot Helmet with a skull on it. To unlock it, you must reach the rank Inheritor, and own every BASE helmet in the game.
Simple: you must be rank commander or higher. Emiles helmet is a helmet of its own.
Commander Helmet. Unlocked after you reach the Commander rank. Rank is currently capped at LT.Cornel Grade 3, Commander is the next rank.
You must get to the rank Luitenant in a game type or for your rank.
no where, except the noose helmet at rank 4 i think.
The Mark VI helmet is unlockable at the rank of Brigadier, and costs 300,000cr. It can first be seen at the rank of Colonel.
Commander
First, rank up until you get to Major, then buy the EVA helmet(It is required or the EVA (C) won't be unlocked). Then, rank up until you get to Commander and EVA (C) or Emile's helmet will be available for 120,000 credits.
The Commando helmet in Halo: Reach is unlocked at the rank of Commander (600,000 total cR and +60,000 from the previous rank which is Lt. Colonel Grade 3). It costs 85,000 cR
Lt. Colonel
no
To get the haunted helmet you need to BE ABLE to buy every helmet and attachment in the armory (excludes Waypoint helmets), so you need to be around General Rank. Then buy the PILOT HELMET and ATTACHMENTS, after this another attachment will appear. This is the Haunted Helmet, all you have to do is buy it for 1cR!!!