Be Gay Do Crime

Helnik? Both want to compensate for past mistakes. Nina wants to compensate for her betrayal of Matthias and Matthias wants to compensate for how he treated Nina's people.

Wesper? Both want to prove themselves. Jesper wants to prove that he's more than just a gangster with a gambling addiction and Wylan wants to prove that he's more than just his inability to read.

I want to preface this by saying I'm neither a fan nor an anti. He's my favourite Shadow and Bone character because he's more interesting than most of the others put together, but I don't like him as a person. Yes, it is possible to separate the two.

I also want to say that I've read the trilogy, both duologies and The Demon In The Woods. Plus watched the show but I'm not going to talk about the show

Motivation

The Darkling had two: Power and Bettering the lives of grisha. They were linked and the second one got twisted out of shape as time went on.

Obviously, everyone can agree that power was a big motivator. He wanted to be the most powerful, to not be restrained by anyone, to be in control of everybody. This would by proxy allow him to better the lives of grisha since no one would dare hurt them.

And he did genuinely want to help grisha. I don't want to hear it. This was his motivation from the very beginning, from since he was a kid. This is what he vowed to do and why he did everything he did, became what he became. You cannot deny that this was a motivation soley because of his methods and ruthless acts.

You have to remember how old he is. How long anger and bitterness had time to grow and swell, how much hate and death and discrimination he has seen. "Protecting the grisha" slowly started to become "Protect them by destroying anyone who dares hurt them" which was accompanied by "Destroy anyone who dares defy me" - this then became "Destroy anyone who dares defy me, even grisha". But it does not erase the roots of the mission or the core theme.

Even when he wants to destroy everyone who dares defy him, he still wants to protect grisha. Not all grisha, now he chooses who deserves it, but they are still important to him.

Alina and Her Powers

The Darkling never truly loved Alina. We can see that in his reaction after she loses her powers. He felt a connection to her because of her sun summoner abilities but that was what his "love" was based on. However the same can be said for Mal who never fully accepted the grisha Alina (and never had to, because she lost her powers anyway :/).

Despite the fact he only had interest in Alina because of her powers, I think some of that interest was genuine. I think he was being genuine when he said that she could make him into a better man - at least, the scene was framed that way. He was toxic and controlling and he wouldn't be a good partner but he thinks that she could fix him. He verbally states this. He thinks it because he genuinely likes her.

He views her as his balance - but this isn't true. He's older and wiser and smarter. Her powers may be his opposite, but he can overpower her. He would've realised this in time and any "love" he felt would've faded. However, it never got to this point.

The Cycle

But despite it all, despite all the bad things he did, you know what? He was right. The persecution of grisha won't end. He'd know. He's tried everything.

I bet he was laughing his head off at Alina and Zoya and all of their friends, wanting to scream I already tried! It didn't work! And it won't. It's naive to think it will work now, when he's failed all these millenia.

The threat of extermination was a last resort. He tried everything else. He TRIED to negotiate! He tried literally everything! He is thousands of years old, and all this time, he was trying to help his people. It. Didn't. Work. That, alongside his greed, is why he ended up escalating.

His need for vengeance is what saved his life on the Reapers Barge and makes him keep on living. It's the cause of his resilience and determination. Without it, he would've given up and died many times over. And yet, it's what almost gets the Crows killed during the heist. He compromises everything solely because he can't handle the idea of Pekka Rollins being punished by anyone's hand but his own. Pekka would have suffered in the Ice Court, but it would not be by Kaz's hand and was therefore unacceptable. In fact, many of Kaz's mistakes can be led back to his maddened need for vengeance.

Similarly, his gloves make people fear him. They add to his mystery and aura of danger. However, their true purpose is to protect him from touch. His gloves are a symbol of his debilitating weakness, his inability to handle any sort of skin on skin contact. What he uses to scare people is used to hide his own terror.

The alias Brekker is similar. He associates the name Rietveld with weakness and naivety, and it is tied to the memory of falling for a con. He replaces it, and his personality, with something harsh and ominous. He is no longer Kaz Rietveld - naive farm boy; he is Kaz Brekker - hardened criminal and conman. However his need to change his name stemmed from his failure - the need to conceal himself so that Pekka wouldn't see him coming.