Instead of a band of metal, he gives her flesh. When they dedicate themselves to each other, to the fire once Rha's al Ghul has perished, they write it in blood, forging themselves warriors of the League and destroyers of Gotham. He carves his allegiance into her honey-colored skin, watching her closely for an indication of pain, but she gives none, holding his gaze as he cuts into her, focusing more closely on the warmth of his hand around her waist than the blood that runs down her back.
He has garnered so many scars—wounds that refuse to heal and seep still, every one a demonstration of his self-sacrifice, that she has insisted he carve himself into her, so she too may bear a scar worth remembering; a scar the is a testament to her dedication.
He does not ask this of her. He would not ask anything of her; the child who saved him from the darkness, for it is to her that a debt is owed. But she knows the truth of it, knows the sacrifice he has made and the way he must suffer daily simply for giving her a chance at freedom. His mask serves as a constant reminder, much as the scars she finds as her fingertips trace over his chest and down his spine.
He does not want to do this to her, to mar her skin in any way that would reflect the monster of a man he has become. He does not want her to become like him; an abnormality, a beast. She is innocence, she is his salvation, but she is insistent, and he is ever the willing servant.
When she slides down onto him, his large hands guiding her hips and his eyes closing for a moment to revel in the pleasure, he is but a tool of her desire as she places the knife in his fist, and as she guides his hand to her back, where she has determined for him to pierce, he is lost to the roll of her hips and the knife slips into her skin more easily than it should have, more easily than he wanted it to. For all of his practiced self-control Bane is lost, and skin slices and blood flows and Talia is bearing down on top of him, her head thrown back and mouth grinning as her chest heaves, the blood tangling with sweat and the sting of the blade a sharp contrast to the pleasure of Bane bucking his hips into her, his girth straining her as it always had.
She comes undone when the brand is finished, the blade sliding out of her as Bane grips the knife in clenched fists, her blood sliding down over her hips and onto his stomach, and he watches with sick fascination as she is reborn; the child of innocence and born of hell is transformed into the Demonhead, her blood shed for cause, her Protector's name on her lips.
But she does not stop, and she will have him know he is hers, completely, as his large palms slip in the blood that has coated her back and smear it down her thigh, gripping her as she marks him as hers; not by pain as he has done, but by pleasure. For only Talia can break through the haze of the medicine that numbs him to all, save her. And his head is knocked back to the floor, his breath a heavy hiss through the mask as he comes undone at the mercy of her thrusts, her smile feral as she shows him exactly who can bring him pleasure, as well as pain.
Years later, when Bruce Wayne asks her what the scar on her back is from, she will respond that it was an old mistake. And it was, truly. Not the scar, but the absence of any others; leaving her Protector in the Pit, letting him take the blows that were meant for her. It is one she will never forget, and never truly repay.