I always find it interesting when people in the ACOTAR fandom call Azriel a great guy because babes, he tortures people.
We don't see it on page. That's intentional. But I think people should really think about it and wrestle with what that means. There is no guarantee that every person he has tortured was guilty. Azriel is a being who takes a knife and causes immense pain to people until they give in and tell him what he wants to hear.
And make no mistake - that's how torture works. There is no magic technique that allows the torturer to know when the truth is spoken. The torturer inflicts pain until the torturer decides what the victim says is true. The victim is left to suffer as they throw out various answers, hoping one will be convincing enough that the pain will finally stop.
And all of this is unnecessary! Rhysand could get the answers out of their heads without pain being involved. He says it's immoral, yet we see Feyre do it multiple times - to Tarquin, to Lucien. So if the mind invasion is worse than torture, we must also live with the fact that Feyre is worse than a torturer, and that Rhysand himself has done worse than torture Feyre when he invades her mind in the first ACOTAR book.
Anyway, Azriel? Not your morally pure boyfriend. He's a person who physically carves a knife into bound and helpless people until they give him an answer that he wants to hear. He causes pain in people, innocent or guilty, and doesn't care enough to quit or refuse.
No matter how kind he is to Feyre, Nesta, Elain, or Gwyn, or Emerie, I have a really hard time forgetting that picture. Imagine him slowly carving into Nesta, Elain, or Gwyn, or Emerie, because Rhysand has become convinced that they're evil and hiding something. Azriel would do it. After all, that's his high lord.