You might find it helpful to think of one of the main threads of figurative language that runs through the entire novel, which concerns the description we are given of Mark and the way that he is compared in various places to a lion. Of course, similes are part of this description, but also metaphors are used to point out the areas of comparison between Mark and the dangerous feline that he is compared with. In the first chapter, for example, Bryon describes himself as being like a Saint Bernard Puppy, which is in marked contrast to Mark:
Mark was small and compact, with strange golden eyes and hair to match and a grin like a friendly lion.
Note the way that it is not only the grin that makes us think of a lion when we look at Mark, but also his "strange golden eyes" and the way that his hair corresponds with his eyes. The way that his grin is described as being "like a friendly lion" seems to capture the danger and strength that is in Mark, as well as his compelling charisma.
This is just one example of this imagery, but you might want to trace it through the novel and find other areas where Mark is compared to a lion through the use of figurative language and see what this reveals about his character. Good luck!