"Oxigen [oxygen], as you well know, is my hero as well as my foe, and being not only strong but inexhaustible in strategies and full of tricks, I was obliged to call up all my forces to lay hold of him, and make the subtle Being my prisoner."

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Then you know that Sam was the true hero of the tale,' Sayna said. 'That he faced far greater and more terrible foes than he ever should have had to face, and did so with courage. That he went alone into a black and terrible land, stormed a dark fortress, and resisted the most terrible temptation of his world for the sake of the friend he loved. That in the end, it was his actions and his actions alone that made it possible for light to overcome darkness.

— Jim Butcher