prometheus god of war

I started playing god of war 1 just a couple of days ago, and I really enjoy it. bride of the water god But now I'm stuck, because i have to defeat the legionnaires with magic shields using the Plume of Prometheus, but somehow I can't get this combo to work. god of war 2 It should be SQUARE, SQUARE, TRIANGLE, but i dont get it done! I tried different intervals and speeds, even