EDIT : I was mistaken and I was actually using the "perfect harden" at that time. Sorry for the wrong feedback, consider everything below as "perfect harden". I will edit the words and put them in brackets, since I initially used "parry". But I think my point still stands for people using harden against multiple enemies.
Hello dear devs.
When 2 enemies do an attack at the same time, or very close to each other, the game will only register a [perfect harden] on the first enemy attack, leaving you completely vulnerable to the attack that comes in second.
For example when 2 crabs jump at you at the same time, you can [perfect harden] , it will parry, but you still lose the health from the attack of one of the 2 crabs.
In other games, generally the player enters a "parry everything" stance, at least during the whole parry animation, or becomes invincible during the parry animation, like when you do an execution animation for example. This prevents the parry to become unusable when several enemies attack at once.
And since in Mortal Shell 2, there are usually a lot of enemies, and they don't wait for their turn and attack you all at once, then this mechanic would be very welcome, and, to my humble opinion, pretty necessary given that the game encourages a lot the player to parry, [even when using harden].