Matt's love for El Patron
Matt has no one to hate more than El Patron, who cloned Matt from himself so that he could harvest organs from Matt later in time when El Patron's body fails. Matt is kept against his will, but he doesn't know it, because El Patron makes his life exactly comfortable enough that Matt is perfectly motivated to do what El Patron wants. He doesn't hate El Patron, because El Patron has successful propagandized him, brainwashing him from birth to agree with what he says. Matt must learn to hate his father for his evil in order to be the hero.
A place called Opium
The town is not American, and it is not Mexican. It is the land of Opium, where addiction and powerful men have led to a lop-sided society where the people are less than powerless. They are truly unlikely to revolt because the system (although exploiting them) keeps them at bay by giving them pleasure. Matt is a good example of this, because his life is so pleasurable that he doesn't want to sacrifice his privileges to admit the truth; the government corruption is a threat against his life.
The wedding and bad news
The wedding in town is good news for most. It brings the community together for singing and dancing and celebration, but for Matt, nothing could be more horrifying than this night, because at the wedding, Matt learns that El Patron is dying of a heart attack. The government will be killing Matt soon to harvest his heart to give to El Patron. The timing is suggestive, as if to say that family is a blessing to some and a curse to others.
The murderous funeral
The funeral of El Patron is already ironic when something very ironic happens. Instead of letting the town celebrate his life, El Patron takes life away from them from the grave, because he poisoned the wine for his wedding before dying. The funeral ends up being an involuntary mass suicide, as if the Patron was solely motivated by hatred and malice. He is a depiction of evil, because even after he is dead, he still takes life away from his community.
The motherless hero
In ancient folklore, often heroes had a regular father and a divine mother, or they would have a divine father and a mortal mother. In Christianity, Jesus has a virgin mother and a heavenly father, but in this book, Matt is the hero, clearly, but he doesn't even have a mother at all. He is only the product of his evil father's DNA. This flips the motif on its head, showing that it doesn't matter who his parents were; all that matters is what he chooses to do. The inverted symbol speaks to responsibility.