Flashbangs should be a kind of grenade what makes the one in effect  blind,cant hear anything, inverted controls,moves slower, and his balance goes to 20, a counter to this would be not looking at it. which could add some tactics like throwing it the enemy looks away and while their looking away you can move to them kill them etc. if looking at it and explodes the effects get shortened if further away. like example enemy 5 feet away - nothing changes blindness takes 13 sec. 8 feet - blindness takes 8 sec. 12 feet - blindess only takes 6 seconds and when hit balance goes to 40, can hear but its wierd. 15 feet - blindness takes 3 sec. balance doesnt get lowered. hears almoust perfectly. and farther than that nothing happens.