Actually,' said Magnus mildly, shrugging off his pajama top and robe, 'because Shinyun stabbed me with a mythological stick and I don't know what it's done.'”
-- Magnus (chapter 2)

Importance: This is one of many examples of understatement as a literary device. Magnus has a wound that is described as a fissure. Though it does not bleed or hurt, there are wisps of red flame emanating. This wound is one of the driving forces behind the novel. Along with the possibility that Sammael will take over the world, the group of Shadowhunters that sets out to retrieve the Book of the White are also trying to save Magnus.

I shall now use it to commune with my mother, wherever she might be found.' He put his hands around his mouth and bellowed at the top of his lungs. 'MOOOOOOOOOOM!'”
-- Alec (chapter 3)

Importance: This is another example of the humorous dialogue, in this case...