Brief advice ; use a blade dancer with invisibility abilities maxed. Arm warp shotgun and rocket launcher and camp by control points your team owns. Go invisible and when the enemy attempt capture take out at least one with a shotgun and run. Also really prioritise picking up heavy ammo and go for easy kills with the launcher. Don't even go after primary weapon kills. You're after a k/do ratio of two so long as all of your kills are warp based. Best of luck; really satisfying when you get there.