I have been trying to take out the Black Iron Knight at the top of the spiral Staircase. Every time I lock on to him and attempt a backstab, I just flail my rinky dink sword into his Shoulder just to watch him laugh at me. I line up with his back, lock on, have shield down, and forward RT is this correct? Also whats the correct way to parry? just LT the same time an enemy is stabbing?