Requiescat in PaceG 10

Very easily obtained in a splitscreen custom game with two controllers. Just make sure that you’re getting behind your dummy account and pressing + holding the melee button, instead of just tapping it.

You don’t want to do the quick rifle bash, you want the takedown animation where you temporarily go into 3rd person view. If you see that, you know it counted. Repeat nine more times for your achievement.