Updated 06-24-2016 05:48 AM
This achievement is unlocked by gaining experience and reaching Rank 20 in ranked multiplayer matches. By the time you finish off all of your weapons for the Soldier of Misfortune achievement you will be in the 16-18 level range depending on how many resets you have done with your diamonds. Since you are fairly close to Rank 20 you might as well finish out the last few levels and grind out the exp. Keep in mind that there is an exp cap of 1500 points per match. Once you log out of the game any extra experience you have gained beyond 1500 in each match will be removed. Since there is no one playing the multiplayer now, the best way to get this done is with two boosting buddies. Additionally if you want to use the glitch method to get to level 30 make sure to not use all of your diamonds. Here is the exp breakdown for all the ranks: