Mortal Sin – How to Beat the Maw of Sin (Final Boss)

Tips for dealing with the final boss.

How to Defeat Last Boss

Died a the first few times I made it to maw of sin so I thought I’d share what I’d learned.

The final boss has the same sort of shield around them that the glowing enemies that drop perks do. You cant damage it while its shield is active. Your weapon will just bounce off. It will eventually go down on its own temporarily, but you will likely die just waiting for it, and it only goes down briefly when it does. The other way to disable its shield is getting a perfect parry, but it will still only go down briefly.

To get a perfect parry you need to press the block button at the right moment just before an attack is going to hit you. You will know you got it right because there will be a blast and it will make a ping sound. If you have the unlock, you can follow a perfect parry immediately with a whirlwind. Often when they attack they will do a weird little feint thing before actually doing the attack.

The actual attacks comes out very quick so you almost need to block preemptively. It has one attack that is faster and comes out almost immediately that is quite hard to parry, but another that is a little slower that is easier to parry. It’s hard to tell by the animation, but this slower easier to parry attack actually has an immediate follow up strike so you need to parry quickly twice in a row.

Another thing that is important to note is that the boss will also spawn scares, so you need to make sure you are listening for the sound and checking the floor. Make sure that you do not have the curse that makes scares slow you because its really hard to escape them if you do, not just in the final boss room but in room C.

This will be hard to see if you have the fog curse, but there is a portal in the far right side of the room that is active after killing the boss if you have completed the previous 3 trials of resolve that open in the hub area in between rooms. This will take you back to the hub are where you can do the final trial of resolve. At the very end you will have to fight two Maw of Sins at the same time. I’ve found the best way to deal with them is activate whirlwind any way you can. It will hit the enemies around you and cause the slow slow motion effect that happens when you hit enemies, which makes it easier to get a perfect parry. Blocking will interrupt whirlwind.

A combination that will make all this easier is mana shield and armor mastery. Mana shield will reduce the damage you take massively (when you inevitably get hit because maw of sin can be hard to parry) but will loose durability very quickly, which is why you take armor mastery. You should probably also have relatively high health because if you health is low you might still have problems even with mana shield. I generally pick up the perk that increases health by a percentage.

The item perk that makes you immune to damage when you do a whirlwind is also very good and will negate a lot of damage. Berserker has this perk intrinsically, but make sure that you also have weapon mastery if you take berserker because you will get very little essence to refill your wizard oil to repair your weapons. berserker also has a potential weapon drop that has whirlwind as its regular attack just like the scythes that reaper gets, so i would definitely search for this (i dont remember what its called). The perk that regains hp when you kill something is also quite good, but if you have mana shield, armor mastery, and the hp perk you already will be taking very little damage so i might skip it for another damage perk in that case.

Before you start a run, it is very beneficial to press t and check all the challenge rewards for each room and plan what route to take based on those. I always go for the challenges that completely upgrade a perk so that you can have as many as you can before you make it to maw of sin.

I also generally don’t open the paid item boxes at all and just loot the corpses and chests to save money to buy perks back at the hub. You can buy two perks each time because the statue that sells them will reset when you beat the trial of resolve.

Another thing, make sure that you always pick up the free perks that show up in rooms even if its something that you don’t really want. You don’t have to worry about getting those perks over and over again from the other free drops after you pick it up. I’ve learned that the only perks that gain that sort of priority are the ones that you buy from the perk rooms. This leads to another point, make sure you get your most important perks from these rooms first because reroll costs will go up in room b and again in room c.

Other curses to avoid other than the one that makes scares slow is the one that makes enemies attack faster because fire wraiths will suddenly become extremely annoying and the one that increases enemy durability damage because durability is precious if you have mana shield or are a berserker. I also avoid drop scares on death and enemies can crit. I would also avoid the waveblade weapon trait because it consumes a lot of durability during whirlwinds, but look for the one that draws enemies towards you when you whirlwind because it surprisingly doesn’t consume much durability.

That’s about all I can think of at the moment. Good luck I guess.