Wings of Fire: Talons of Power (Tui T. Sutherland)
A long time ago, I-Mockery put out an article of some of the writer's least favorite comic book characters, and at the end the writer noticed how many of the characters he'd included had mind control powers. I bring this up because "enemy who can read and control minds and do anything, and is therefore boring as dishwater" is the root of the problems with this book.
Queen Scarlet was scary. She was ruthless, erratic, driven even crazier from having her face half-melted off by acid, and yet somehow grounded. Darkstalker, but contrast, is totally fucking boring. As well as being able to read minds and see the future, Darkstalker is an Animus dragon. The first five books only briefly touched on Animus magic, and from what I recall it didn't tell us more than that Animus dragons could enchant objects to do... something, like turn into a castle, dance around, come alive and kill certain people when nobody else is around, or find the perpetrator of a crime, but each spell costs the dragon some of their soul depending on how powerful the spell is. Here we finally learn Animus magic means "An animus dragon can do whatever the hell they want." They can make dragons immortal and invincible. They can rewrite another dragon's personality. They can send plagues in an attempt to genocide an entire race of dragons. They can even grant and suppress Animus abilities in other dragons. And, where things start getting really messy, they can grant immunity to all those spells. Sutherland wants to play up how dangerous and unstoppable and frightening Darkstalker is, but a villain who's too powerful is one you can get lazy with.
Darkstalker has already made himself immortal and invincible with his magic, but then he enchants an earring to make all dragons immediately trust and like him, and alert him when other Animus spells are cast. Like, anywhere in the world, apparently. What was stopping Turtle from flying out to the middle of nowhere and enchanting an object to allow him to cast Animus spells without Darkstalker's Animus magic detecting spell detecting it? Darkstalker's earring only informs him when a spell is cast, not what the spell was. And Turtle can enchant objects to make the wearer immune to Darkstalker's spells, after all, and his magic stick that prevents Darkstalker from seeing him still works, so I don't think it's about which Animus dragon is more powerful? Darkstalker would have picked up on that one, flown out to wherever Turtle was, and found nothing because of Turtle's magic stick, assuming Turtle didn't beat tail out of there beforehand. But after that, Turtle would be free to cast as many spells as he wanted, right? If Darkstalker caught on, could he cast a spell to allow him to penetrate Turtle's cloaking spell? And could Turtle cast a spell to block that spell?
And then it's detection/anti-detection spells all the way down. I did not even notice the "Turtle" joke until I wrote that.
Oh shut up about the magic system, how does the story hold up? Well, the story is so tightly interwoven with the magic system you can't separate them. Turtle is just one of two dozen Seawing princes (there are so many because the princess eggs kept getting smashed by an assassin and they kept having to pump out offspring until a female finally survived, as explained way back in The Lost Heir) and gets lost in the crowd. Except Turtle is an Animus, which he's kept hidden from his family for years. And the only thing that could take down Darkstalker is another Animus, but thanks to Darkstalker's Animus-detecting earring, Turtle can't use the one thing that separates him from his brothers. Except he, like, totally could. For the reason I just explained.
At best it's best a lackluster way of forcing Turtle to play spy instead of immediately taking Darkstalker down so Sutherland can write two more books. At worst it lets him off the hook for being a total coward. But let's pretend this obvious solution wasn't staring us in the face, and there was some reason Turtle couldn't cast an anti-Animus-detecting spell. It's not terrible, I guess. Darkstalker being so overpowered he circles back around to being boring aside, Turtle having to spy on Darkstalker plays into his to desire to go unnoticed, until he finally grows a pair and has his big "Fuck this, I don't care if Darkstalker finds me anymore" moment.