The hardest part to any Soulsborne game is figuring out how to overcome a boss. Mortal Shell approaches them with a bit more ease, though this is a fight that is less about equipment and positioning and more about tactic and skill. Since this can be very difficult for people, we wanted to make it easier by explaining how to defeat every boss.
Since Mortal Shell is a non-linear game, one where you might lack certain resources before any given boss, every boss guide uses the hollowed sword that you start with. Make no mistake, this weapon is extremely powerful and well worth maxing out.
If you are having issues that this guide does not help you overcome, I strongly suggest going back to the starting base and purchase as many rats as you can. These are extremely valuable in regards to healing and can make any boss, regardless of skill, easy.
Beyond that, remember that any fight is doable, provided you don’t get trigger happy. More mistakes stemmed from rushing things than anything else.
How to Defeat Hadern
Unlike every other boss in Mortal Shell, Hadern appears multiple times. First as the tutorial boss and then again to unlock the other weapons. Each fight is a little different, so we included a guide for each version, though one of the best universal tactics is to harden either immediately after he does or right before, so you can gauge what his cooldown is at.
Tutorial / Hammer and Chisel / Martyr Sword
For the tutorial hammer and chise and martyr sword version of Hadern follow the same basic tactic. Get distance, wait for him to attack, harden and then punish. Getting greedy will almost always result in him doing the same to you, so your best bet is to just force him to do the same move every time. If done correctly, he should die without any issues.
Unlike the previous fight, this time you want to keep your distance until you know Hadern has a harden. When you’re certain, rush him and he will almost always attack and harden. Simply wait it out, rush him and then punish.