According to Adam Smith's The Theory of Moral Sentiments, proper moral sentiments may be defined as how a disinterested observer would think someone ELSE ought to feel in a given circumstance. Given that yardstick, I am not myself convinced that your MC is wrong. My own reaction is that anyone who isn't horrified by committing brutally cruel murder is morally deformed - no matter how important it happens to be for that specific carnage to continue.

It sounds as if your character's moral compass is functioning correctly.

Organic characters don't always feel or act as the author intends. In the case that your characters grow organically, you have to negotiate with the character, and accept that you can't always steamroll them into occupying exactly the place the plot called for them to occupy at a particular point in the plot's progression.

I know this will provoke some people, but: Good guys don't murder, can't murder.

Murder is "the unlawful killing of another human without justification or valide excuse, especially the unlawful killing of another human being with malice aforethought."

What you're talking about here must - at best - be killing, because you are putting a very specific constraint on those people: They're the good guys and in our society murder will never be seen as good.

And this is not about semantics. I'm not saying "haha, you used the wrong word", I'm saying you think in the wrong terms. Wrapping your head around "Murder is good" will be hard for the reader and that IS an understatement. Any effort put into letting the MC come to realize "their murder is good" is therefore wasted. You need to convince your reader, if you really want the MC to accept the good guys as that, or otherwise the disconnect between reader and MC will be too big (unless they're sociopaths, then they'll probably be fine with murder).

So how do you convince the reader that the good guys are the good guys? That is the important question. Because if you want to explicitly define your MC as a hero/anti-hero/villain/anti-villain you can only do that by defining what is good and what isn't to the reader. If you don't, the readers will do that for themselves, in the confines of their own moral compass. And you have no power of that. They might see it the way you intend to, but I wouldn't bet on it.

The first clue to that is: How did you convince yourself that they're the good guys, other than simply saying "I define them as good guys"? That, will not do.

EDIT:

As an after-thought: You will never be able to create a world where murder is allowed or accepted, without the reader (violently) rejecting it. This world would be so fundamentally different to ours, that there's no other option for the reader.

Let's take a popular example: Dexter. Dexter's saving grace for many people was, that he only ever killed criminals who - in the eye of the general populace - deserved to die. For the average viewer he had a legitimate reason to kill them (not murder, phrasing). I personally hate that series, because I think he hadn't. And people, in general, who think he hadn't had a legitimate reason, tend to disconnect with and dislike him. You will never convince those people that he was a 'good guy'. And if he had killed an innocent without very good reasons, the character would've been instantly disliked by a lot of people. There's a list of "innocent" people Dexter killed and lo and behold, he always had a "good reason". Some where drug dealers or rapists, others he killed in self-defence and at least one person he killed on request of said person. Here's the link: List of "innocents"

A perfect example. The series creators had to convince the viewer that Dexter was the good guy. Not by any non-contrived scene or event, but by appealing to the viewer's moral system. The reader is the key, not the main character.

The way I see it, it isn't about forcing the issue that the good guys are good. If you instead look to the avenue of dehumanizing the victims, it's far easier to rationalize the actions of the good guys, even to the point of supporting them. There have been multiple examples in history of where this technique has been used against a group of people. But, on a lighter note, this technique is used in all sorts of books, tv shows, and films. Look to examples where, as an onlooker, you exclusively support the good guys as they kill. even killing humanoids:

• Supernatural, they kill vampires, werewolfs, etc, and despite them being human-adjacent, with a lot of shared characteristics, you don't think less of the MCs for killing them.


• Firefly, Reavers "Human's gone mad on the edge of space". They're human, you feel nothing when they die.

Of course, another avenue is, they're preventing something so profoundly bad, that they only can be good guys. They are sacrificing these people for the good of all life. If spun properly, this can have the same effect, especially if you explore the psychological toll it takes on these characters. Show them haunted by their actions, or a flashback to a past where they cared, and they become identifiable as good.

Killing is never good and shouldn't have a (purely) positive effect.

Killing comes at a price for the killer

Sometimes killing is a necessity, for example for a hunter-gatherer tribe when they kill their food or when a veterinarian puts down an animal that is beyond healing and would only lead a life of extreme suffering. But the hunter-gatherers have rituals in which they thank the animal that it gave its life for them and allowed them to live, that is, they ascribe some voluntary aspect to the victim to absovle themselves of the wrongness of killing. And the doctor as well only stays sane by believing that killing his patient is the best for that patient.

The only other time when killing can be legitimized by the killer is when killing a perpetrator is the only way of averting a danger from society, such as in war or in the death penalty. Then, a complex system of legislation and jurisdiction absolves the soldiers and executioner of personal guilt, but it comes at a price:

• 
  

  soldiers and executioners are often shunned by parts of society

  
  
  

  German author Kurt Tucholsky, who himself was a soldier in Word War I, coined the statement that soldiers are murderers in 1931, and until today that slogan is a fundamental attitude of the peace movement worldwide:

  
  
  

  

  
  
  

  Executioners have often been held at a distance by their society. In medieval Europe, for example, their houses were placed outside of the safety and society of the city. This is an image of the executioner's house (Henkerhaus) in Salzburg, Austria, which clearly shows this social exclusion and loneliness:

  
  
  

  

  
  

Whether your "good" torturers – for "slowly carving runes" into the bodies of other human beings is torture – will be only avoided by their community in the way the medieval hangman was avoided, or if they are seen as inhuman savages in the way that we abhor the ISIS beheadings, will depend on the story you want to tell, but it is unlikely that their community will unequivocally view them as heroes.

The second price, besides social ostracism, is a more personal one. Your killers will need a very strong ideological belief (similar to that of the ISIS executioners), if they want to remain sane after their deed. Many soldiers suffer from posttraumatic stress disorder, and not only because of the danger to their own lives, but often because of the deeds they found themselves forced to commit to survive. Policemen and -women, when they had to kill a perpetrator, are given psychological support because killing is an extreme stressor for the killer. If someone chooses the profession of torturer in a modern society, where other means of subsitence are abundant, they must have a certain kind of personality where either emotional coldness or a fanatic belief in some ideology will legitimize their deeds for them, and if they have the slightest doubt their deeds will traumatize them.

Here are only two articles about the traumatizing experience of having to kill:

• https://www.mlive.com/news/index.ssf/2012/06/experts_the_psychological_afte.html


• https://www.psychologytoday.com/us/blog/talking-about-trauma/201402/death-becomes-us-the-psychological-trauma-killing

I am sure you can find more in-depth information if you research this topic.

As a reader I would only sympathize with your protagonists if:

• the killing was unavoidable to avert the horrible death of numerous innocents


• the executioners/ritualistic torturers suffered for their deeds by being ostracized and emotionally broken (you could of course show how they later came to terms with their deeds)

I see three ways:

1. A dramatic/traumatic event:
   You want to change your MC dramatically, so a dramatic event is a believable reason for that. The dramatic event would be probably something like the MC having to act like the good guys. He might refuse, and suffer a huge emotional loss because of it. The person he's trying to spare probably dies a horrific death as well (or worse).
   Anyway, thats for you to decide.




2. The good guys were more similar to the hero than he thought.
   They appear cold on the outside at first, but they feel the same way he does. They don't want to do it, they have nightmares because of it, they cry out of guilt. So you don't have to change your MC.

Both of these, basically make the MC more like the good guys. Most people don't think of themselfes as a bad person, so when he is doing the same and feeling the same as these guys, he accepts them as good guys.
Even if he sees himself as a bad human, then he and the "good guys" are as good as it can get in this world (or he would do someting differently).

3. Lay it on thick.
   Use standard techniques to make people likable.
   For example: They love animals, they help people in need/distress when they gain nothing from it and no one will know they did it. They are loved by their family.They are funny. And so on... theres a reason why these techniques work.
   Show that they themselfes are willing to take the same sacrifice as they force on others.
   And most importantly to come back to an earlier point: They feel bad about what they do. I am not sure if that fits with your story, because you said they are "unapologetic" but I feel like that leaves lots of room.

I think it's almost impossible to make them accepted as the good guys, if they don't feel bad about what they are doing.

Assuming the MC also believes himself to be on the side of good, another way of stating that the MC believes what they're doing is "good" is to say that the MC would do the same thing if he were in their shoes. So, make him make that choice. If he has to accept that killing someone himself is a necessity, and he's still "good," then by extension, they are as well.

Make it personal to the MC. Anyone can say they wouldn't do that when analyzing it logically from the outside. But what if it was to save his spouse, or his children, or his best friend, or 1000 complete strangers vs 1 life? What if the 1 life was freely given, and the person was willing to sacrifice themselves for the greater good? Would he deny them that and doom everyone else?

What if, in the end, the MC decides the good guys need to kill HIM?

Ritualistic murder is all about compromise.

First, your main character sees a reason not to shun and dismiss the ritualistic murderers completely. Maybe he has a goal that can only be achieved by slowly carving runes into somebody until they die. Maybe he wants to change the system from the inside; either to minimize the amount of ritualistic murder, or to help guide it towards more deserving targets. Maybe he's surrounded by people that believe in the murdering strongly enough that he can't openly speak out against it.

This is reinforced when it turns out to work. Maybe the "good guys" aren't perfect, but by golly, look at them getting things done. Meanwhile, perhaps some other group of people is trying to do good without any murders involved, and they turn out to be completely ineffectual, only capable of trite moralizing and having to be rescued by the ritual murderers.

Once your main character has taken so much a single step towards accepting ritual murder, have that step be one step too far. Anyone else who thinks that killing people by carving runes is bad should decide that by failing to decry ritual murder at every possible opportunity, the main character is as good as one of the ritual murderers himself. (If your main character refuses to take this first step, this can be due to a misunderstanding instead.)

Meanwhile, the ritual murderers welcome the main character. Some of them are perfectly nice people aside from the torture. Maybe they even punish excesses, and look down on anyone who looks like they're enjoying the ritual murder too much. All other options failing, the main character has to work with the "good guys" to accomplish anything.

It's nice if the main character can point to concrete good things he's achieved, and moral lines he hasn't crossed, only to have the people that are inexplicably anti-ritual-murder dismiss them entirely. This will certainly drive the main character further into the ritual murdering crowd, and as a bonus the readers will get defensive on his behalf.

You shouldn't have your MC think they are "good". In the context they may be necessary, but there's no society where torture and murder are good acts. The unapologetic torture-murder you describe will be a moral event horizon for every reader.

Perhaps the faction can negotiate for what they need. Offer a deal to death row inmates, those about to die of disease, or die of old age their life in exchange for something they need more than their brief remainder of time on Earth with a "your life cannot be taken, it can only be given" requirement to the ritual. Essentially the faction promises to help undo their criminal wrongdoings or ensure a loved one left behind will be taken care of in exchange for the victim's ultimate sacrifice. An offer to be a hero with their dying gasp.

This would not make the faction good, they're still horrifically killing people who don't deserve to be tortured to death. But it makes them sympathetic, distances them from cold-blooded taking of a life against the victim's will, and paints a picture that they value and honor those who they sacrifice no matter how wicked they were in life.

Some ideas:

• show proof that those rituals DID achieve something good


• may be..rituals are really needed and victims ARE consented ? (if they knew they will be killed anyway because they are "society's worst" and they sacrifice will help people, why not consent? . Don't say it's not possible - think of kamikaze)


• show proof that victims are really "society's worst" and/or they condemned by law/etc as such AND their families are paid for this.

Make the consequences personal.

Most humans are fundamentally selfish. No matter how altruistic someone believes themselves to be, they're still going to be more invested in things that they feel a connection to.

Sure, MC knows the bad guys are bad, but while they're only doing bad things to other people, it's hard to see them as bad enough for stopping them to be worth the price of ritual murder. Then MC does something (whether accidentally or deliberately) to disrupt one of the good guys' rituals, and that gives the bad guys an opportunity to do something that leads to the death of a close friend or family member. Now MC realizes how important the good guys' actions are, and has both guilt and revenge as powerful motivational forces for supporting them.

You could probably lead the reader and MC in with a "Just this once" situation, and then have you have broken the problem into a fuzzy one of when to kill people not just whether to.

You could start by killing the absolute worst in society to save something the reader and MC cares deeply about. It would also be more persuasive if the sacrifice is the guilty party of what they are trying to protect. As an example killing a drug addict who took a bribe to assist the dark forces, and in order to make it right they are going to kill him sounds a lot more reasonable than if they request an unrelated murderer from prison who has been quietly in his cell for the past seven years.

Doing something in the heat of the moment is also more acceptable, eg killing a knife man before he kills someone is different to capturing him safely and then taking his heart to save his victim. Your character could make his first sacrifice kill in combat with the sacrifice or as the evil is closing in on him.

I personally think that once MC accepts that there is such a paradigm as "Killing can be good", he busted. He has become the enemy.
Once you adopt the methods of the "Bad" you too have become one.