Learning how to parry in Mortal Shell will probably save your hide more than a few times. The concept is simple in that you can reflect an attack if you time it correctly. But how do you do the Mortal Shell parry and when do you get it?
How to do the Mortal Shell parry move
Before you figure out how to parry, you’ll need to get the ability first, despite the controls implying that you already have it at the beginning. You get the ability to parry in the Fallgrim Tower when first interacting with the Old Prisoner. He’s the big locked up guy in the tower that the game pushes you to go to at in the very beginning of the big green area. It’s right by the first Sester in the game, too (the doll-like checkpoints). You can do this right in the beginning of the game after the tutorial.
After entering the open door and seeing the Sester, go up the stairs and visit the Old Prisoner. Your first interaction with him will grant you the ability to riposte attacks.
By hitting the L1 or LB button, depending on your console, you can parry an incoming attack. You have to time this well as the seal you whip out to parry needs to be hit while it flashes like in the above picture. You’ll know when you do a successful parry since a loud noise will play and the enemy will recoil. Be sure to hit the R1 or RB button to do the all-important riposte.
Most enemies in the game have pretty obvious tells and the timing is more forgiving that other Soulslike games. Also Hardening at the right time can save a botched parry so keep that in mind.
There are three different types of parries you can earn after killing bosses and returning to the Old Prisoner. They all are performed the same way, but have unique effects. One simply gives you a good chunk of health back, another tosses a sticky bomb on the parried enemy, and the final lets loose a big attack that can hit other enemies with its final shockwave move. You can quickly switch between all three when you press the Triangle or Y button.
You will need Resolve (the yellow bars above your health you build by hitting enemies) to perform these moves. You can technically parry without having Resolve but you will not be able to a special attack afterwards.