A cunning warriorG 40

To unlock this achievement you simply need to level up the trait card ability to level 3. The first trait cards are purchased after you reach level 15 in the game and can be found with all the other Star Cards. Choose one card and in a multiplayer match you will need to get kills without dying to level the card's abilities to level 3. Here is the list of cards:

Bodyguard - Decreased damage
Survivalist - Faster healing regeneration
Scout - Enemy radar invisibility
Bounty Hunter - Power up generation
Sharp Shooter - Weapon cool down reduction