The tide of people (Metaphor)
Observing the crowds of Ketterdam outside the Crow Club, Kaz "watched the tide of people flowing past the portico's black columns, beneath the watchful eye of the oxidized silver crow that spread its wings above the entrance." The crowds of people coming into and out of his establishment are much like the tides he once struggled against, using Jordie's dead body as a raft. The comparison of the people to the flowing tides separates Kaz from the rush, aligning him instead with the watchful silver crow.
A trained falcon (Metaphor)
When Inej eavesdrops on Kaz, she feels slightly guilty, but she observes that “he was the one who had turned her into a spy. You couldn’t train a falcon, then expect it not to hunt.” The metaphorical comparison of herself to a falcon implies that a person's nature, whether inborn or taught, dictates their actions beyond guilt or blame. You can't hate someone for what they are. When she compares herself to a trained animal, the reader can see that Inej still has quite a low opinion of her own autonomy; she might not be a lynx anymore, but her nature is still more animal than human, and when Kaz calls her, she answers.
A dark fist (Metaphor)
Nina describes the towers of the prison fortress Hellgate as “a dark fist of stone thrusting up from the sea.” The metaphor illustrates the violent nature of Hellgate, as well as its unnaturalness. A fist thrusting up from the sea gives a sense of something unnatural rising from the depths, or perhaps a human who is drowning and merely trying to stay above the waves.
Like a trail of blossoms (Simile)
In a flashback explaining his backstory, Kaz remembers that “After their father died, crushed beneath a plow with his insides strewn across a field like a trail of damp red blossoms, Jordie had sold the farm.” The comparison of his father's violent farm accident to blossoms—especially blossoms in a field near a city based on Amsterdam, which is famous for its tulips—relates death to growth and beauty, perhaps providing insight into Kaz's blasé engagement with violence. Kaz views violence and death as a means to an end; his callous outer shell was first created when his father's insides were spread like flowers.
Honey skin (Metaphor)
Nina is surprised by how different Matthias is after a year in Hellgate. “His skin had been gilded honey; now it was fish-belly white beneath the grime.” Metaphorically stating that his skin was honey evokes both visual and taste-based imagery, which suits Nina, who loves to eat and revels in the luxuries of life. Now Matthias's skin is fish-belly white, as it presumably was when they were half-drowned together after the shipwreck. Matthias has transformed from something delectable to a grimy fish belly—certainly not a delicious image, communicating Nina's desire for Matthias as well as her concern for his current physical state.
Like meat for roasting (Simile)
Kaz sees that some members of Pekka Rollins's crew have been caught and impaled: “Kaz tracked Nina’s gaze to the top of the ringwall...where five men had been impaled on spikes like meat skewers for roasting, backs bent, limbs dangling.” Comparing corpses to meat skewers for roasting forces a sensory experience on the reader, evoking barbecues, meals, and safety, while simultaneously describing a horrendously gory image. Repeated gerunds (roasting, dangling) give a sense that this is a current event, as if those dangling limbs might spring to life.
