You need to guard break in the very first frames after you parry. If you guard break just as you finish your parry animation, your character will dash forward and guard break. You don't have to press any direction with the movement keys. The game just assists you with a dash guard break because you parried. If you miss the frame window, you will just guard break the air in front of you with no dash forward, and you'll get punished.
Practice the timing in practice mode vs level 1 bot and you'll see the huge dash forward that automatically happens after you parry then guard break. All classes will do this, but not all classes can benefit as much from a guard break.
It's worth noting that attacks parried from very long range can't be reached with the dashing guard break. The best example of this is the Nobushi who pokes from so far away, that a parry won't get you a guard break. Other classes can poke at you from the tip of their long range attack and avoid the guard break, but this isn't that common. Typically you can guard break almost any class after parrying their attack, and this is almost always the most punishing followup to a parry. Whether or not this is the best way to implement rewarding a parry is another story, but this is direction that Ubisoft is currently running with the game.
1 people found this helpful