Like something was behind him
Cassius describes how Lorn felt like he was trapped by himself, "like something was behind him beating him on, something to the sides winnowing his path." This simile is used to emphasize how Lorn didn't feel as though he had free will, and was controlled by forces outside his control.
Full of poison simile
Darrow describes Victra using a simile in the following passage: "Victra thinks she's wicked and keeps pretending like she just wants revenge. Like she's full of poison." By describing her as being "full of poison," Darrow suggests that Victra is bitter and resentful.
Rusted iron simile
During his stay in prison, Darrow is confined to a small space: "My joints fuse like rusted iron." Here, this simile is used to describe how Darrow's joins have become fused as a result of staying in one position for a long time.
Hair simile
Darrow uses a simile to describe Mustang's hair: "hair rippling as would summer hay fluttering from a farmer's wagon." By describing her hair in this way, Darrow connects Mustang with nature, and emphasizes how much he misses her.
Odysseus simile
Darrow uses a simile to compare himself to Greek hero Odysseus: "He broke the walls of Troy with his wooden horse. Like I broke the Bellona armies in the Iron Rain over Mars." By comparing himself to Odysseus, Darrow emphasizes his heroic qualities.