"I doubt he himself has any idea what it's like to be so paralyzed by fear that you feel small and insignificant. But he knows just how to arouse that fear and spread it, in people's homes and their beds, in their heads and their hearts." (3.40)
Dustfinger characterizes Capricorn's power as coming from his ability to spread fear so easily and effortlessly. Because when people are afraid of you, you gain power over them, plain and simple.
"I'm happy to make promises, especially promises I can't keep." (17.61)
Oh, Capricorn, you sound so diabolical here. He's basically admitting that he makes promises in order to manipulate people into doing what he wants, and that he doesn't care if he can't keep them—in fact, it's better that way. It kinda makes us wonder why anyone who hears Capricorn talking this way (such as his men) keeps associating with him, since he's pretty much guaranteeing to fall through on his word at some point.
"This will provide her with reliable protection from snakes and fierce dogs but not, of course, from Basta himself, who will be kind to her only as long as I say so. And that in turn will depend on whether I am pleased with your services." (17.95)
As an example of Capricorn being diabolical and manipulating people, we see him gaining power over Mo by having Basta "protect" Meggie. Blackmail is a pretty potent way of gaining power over someone, and Capricorn sure seems like he knows what he's doing here.
"They're afraid of you, Mo!" whispered Meggie. She could see the trepidation even on Basta's face, although he was doing his best to hide it by assuming a particularly bored expression. (18.28)
Unlike Capricorn, Mo doesn't seem to lust after power or enjoy it when people are afraid of him. Meggie notices that Capricorn's men (even Basta) fear Mo after this first demonstration of his power to read things out of books. And why shouldn't they be afraid? It's the kind of skill that makes you powerful, and they don't know Mo as well as Meggie does, so they have no idea what he might do with that kind of power.
"'Power is all that counts,' he taught his son. 'Rules are made by the strongest, so be sure that you're the one who makes them.'" (34.44)
Fenoglio's account of Capricorn's upbringing is pretty disturbing. Apparently Capricorn's dad, a lowly blacksmith, was obsessed with the idea of power, and so he drilled it into his son. In theory, it shouldn't just be the powerful folks making all the rules, and that's why we live in a democracy… but they must not've reached that stage of political thought in Inkheart. Whoops.
But a day had always come when the web of fear, so expertly spun by Capricorn, tore and the attention of the police was drawn to his men and what they were up to. (37.3)
Capricorn's bigger than a small-time crook, but not quite as powerful as a criminal organization that's managed to penetrate all levels of law enforcement and government. So while he can intimidate a handful of regional police officers to keep quiet about his operations, he probably couldn't evade notice at the national level. This is probably a good thing.
"I really could read better once," he said, sniffing. "But this constant fear…" (42.23)
Poor Darius—his reading power has been affected by living in fear under Capricorn's watch. It's easy to think of situations where being under intense pressure might throw someone off their game, but it seems like Darius has a particularly bad case of anxiety. And why wouldn't he? His life hangs in the balance, as Capricorn has complete control over whether Darius eats, sleeps, and lives or dies. That's a scary amount of power to have to live under.
"I, Fenoglio, master of words, enchanter of ink, sorcerer on paper. I made Capricorn and I shall destroy him as if he'd never existed—which I have to admit would have been better!" (46.24)
Fenoglio is beginning to sound like he thinks of himself as an all-powerful creator figure. And while sure, as an author he is the creator of his own characters and worlds, it takes the enchanted voice of a reader to bring his creations to life. Maybe it's a chicken-and-egg question as to who's more powerful, but either way you slice it, Fenoglio's starting to sound a little conceited here.
At that moment Meggie's mother raised her hand. The stone hit Basta on the head. Astonished, he spun around, looked at her as if trying to remember who she was, and put his hand to his bleeding face. (49.57)
Go, Resa. Basta lets his guard down around her because he is focusing on trying to cut up Dustfinger, and besides, she's only a woman, right? Wrong. Resa is able to take charge of the situation and strike out at Basta, in large part because it is so unexpected. Now that's real power: being able to take down someone bigger and badder than you, simply because you weren't on their radar to begin with.
For Meggie had a plan: She wanted to learn to make up stories like Fenoglio. She wanted to learn to fish for words so that she could read aloud to her mother without worrying about who might come out of the stories and look at her with homesick eyes. (59.27)
By the end of the book Meggie has witnessed extreme violence, social and emotional manipulation, and many instances of reading and writing in order to change events. Guess which one she picks as her goal? That's right, she goes the way of the written word. This says a lot about how powerful she perceives writing to be. Plus she's motivated to learn how to write so that she can connect with her family in a safe way, without worrying about reading people into or out of books.