Reach Diamond Grav Commander Rank
The 4 rank trophies are Boostable with 2 players.

There are 20 ranks to reach in MP mode. Diamond Grav Commander is the last rank achievable and for this one you need to earn 800,000 XP to reach this rank AND unlock this trophy.

Here is the complete list of Ranks to unlock (the XP needed is on the left):

0 - Bronze Grav Officer
10,000 - Silver Grav Officer
20,000 - Gold Grav Officer
40,000 - Bronze Grav Sergeant
60,000 - Silver Grav Sergeant (Half Sack )
90,000 - Gold Grav Sergeant
120,000 - Bronze Grav Lieutenant
150,000 - Silver Grav Lieutenant
180,000 - Gold Grav Lieutenant
220,000 - Bronze Grav Captain (Soldier )
260,000 - Silver Grav Captain
300,000 - Gold Grav Captain
340,000 - Bronze Grav Major
390,000 - Silver Grav Major
430,000 - Gold Grav Major (Enforcer)
490,000 - Bronze Grav Commander
550,000 - Silver Grav Commander
620,000 - Gold Grav Commander
700,000 - Platinum Grav Commander
800,000 - Diamond Grav Commander (Man of Mayhem)

Thanks to Licensedshoes who has provide some great help on this odyssey:

If you get around 30-40 kills per match, given that you don't complete any challenges in that match, you will probably net around 1000-2000xp. Gravity finishers give you 30xp, headshots 25xp, and all other kills give you 20xp. Once all of the challenges are done, it will still quite the grind for xp to reach Diamond Grav Commander....

Crater is a good map to boost for xp if you have a full lobby of idlers. One person can stand at the top of one of the cliffs where the heavy sniper spawns and if you stay up there you see most of the spawn points. Sit up and get headshots all match and you can end with anywhere from 80-100 kills. I was getting around 3000 XP per match doing this.

After all challenges are completed there is still around 100,000 xp that needs to be earned to make it to Diamond Grav Commander.

It's VERY important to know that you must play in Quick Matches, because if you play in "Create Session" you won't receive any XP.


Also it's extremely recommended meanwhile you are reaching the highest rank, try to unlock as many Challenges as you can (Weapons & Basic) because you can earn extra XP for every Challenges unlocked. So keep tracking of the Challenges too.