Silent But Deadly
From Halopedia, the Halo wiki
Silent But Deadly
Silent But Deadly is an achievement in the Halo 2 Vista. It is worth 20 Gamerpoints and can be earned when you kill 7 opponents from behind in a row without being spotted, any level, any difficulty.
It is represented by a 16-pointed star, a green fireball on the star, and the face of a ninja on the top.
