There's some good characters in Hannibal. The prose itself is pretty good. But there's also a lot of stuff like Harris not knowing how to wrap up the story of characters like Barney so we get "Margot gives him his money and he gets to go around the world seeing Vermeers." Because we learned that Barney wanted to go around the world and see all the Vermeer paintings. BUT HE DIDN'T GET TO SEE ONE BECAUSE HANNIBAL WAS DERE!
The over the top nihilism grinds the reader down. The attraction of Lecter as a character is the contrasts. He's completely evil and boring in Hannibal. Mason Verger is an extreme pervert sadist so he's supposed to be worse, but we see multiple instances where Hannibal is just as cruel and clearly enjoying it. There's no more illusion that the cultured, elegant side of Hannibal means anything except as another demonstration of his superiority to everyone and everything. Jack Crawford dies entirely alone and entirely defeated because muh nihilism. Ardelia's outrage and grief at losing Clarice is just another thing ground down into nothing by the uncaring universe because muh nihilism. It don't matter none a this matters
Kidnapping Clarice and drugging her and trying to brainwash her into Mischa is not the Hannibal of Silence. That Hannibal never would have tried that shit with that purpose. His character is now contradictory. He's supposed to be completely different from normal human beings and other sociopaths, but why he's a sociopath ends up being just another muh childhood trauma. His fantasy about brainwashing Clarice into Mischa while he has her blitzed out of her skull on a double handful of extremely exotic drugs, and actually trying to do it, is something that should be beneath Hannibal Lecter. Lecter doesn't think psychiatry is a science, but his education in psychiatry guides his thinking of how to brainwash Clarice. His ability to attract the ladies is very well-established, but only Clarice hits his Mischa button. For some reason. Which is never established. He just likes her because she's kinda sorta Mischa because she is, okay? And she can cure his pain because she is. And she does. To wrap up nihilism fest 1999 we get a happy ending for him and her. Hannibal Lecter was supposed to be beyond that shit. But he isn't. Shut up and enjoy the expertly sauteed Krendler brains
tldr giving Hannibal a kinda mundane backstory and lazily developed motivation in his relationship with the protagonist, setting him free only to use him as merely another nihilism hammer to beat the reader's head in with - in a novel that has almost nothing but nihilism hammer characters - and topping it off with Hannibal and Clarice living happily ever after is very fanfic and very disappointing