Posted originally on the Archive_of_Our_Own at https://archiveofourown.org/ works/13906887. Rating: Explicit Archive Warning: Underage Category: F/M Fandom: Batman_-_Fandom, DC_-_Fandom Relationship: Batman/Batgirl, Bruce_Wayne/Cassandra_Cain Character: Bruce_Wayne, Cassandra_Cain, David_Cain, Jason_Todd, Barbara_Gordon Additional Tags: bimbofication, bimbo, Bimbo_Fetish, Sex_Slave, willing_sex_slave, Weird Romance, Twisted, Mentally_unstable_characters, Kissing, Groping, ass grabbing, ass_pinching, Older_Man/Younger_Woman, Age_Difference, Underage -_Freeform, Sort_of_dubious_consent, big_age_gap, No_Sex, Love, Dark, Kind_of_Snuff_but_not_really, Mindbroken, mind_wipe, Drugs, Consensual Brainwashing, kind_of_incest, Adopted_Daughter_Sex, Father-Adopted Daughter_Sex, Father-Daughter_Sex, Submissive_Batgirl, Submissive_Female Characters, dominant_Batman Series: Part 9 of DC_Fetish, Part 6 of Batman_Fetish Stats: Published: 2018-03-08 Words: 1127 ****** Sink Into You ****** by StannisTheMannis Summary Cassandra Cain. Raised to kill. Murdered a man at eight years old. Trained all her life by an abusive father to be the world’s deadliest assassin. Is it any wonder she’d rather forget who she was? Is it any wonder she’d want to erase the life she once had, to become something else entirely? Is it any wonder she’d decide to dedicate her life to pleasing the one man who treated her right? Notes See the end of the work for notes “Are you absolutely sure you want to do this?” The vigilante known as Batman stood in the cavernous center of the Batcave, his cowl pulled down to reveal the handsome features of Bruce Wayne, contorted with worry and conflict. In front of his stood Cassandra Cain, known to the public as the Batgirl. The teen hero was fully undressed, and Bruce’s eyes roamed over her lithe body, taking in her long muscular legs, her tight little ass, her breasts barely bigger than a prepubescent boy’s, with tiny brown nipples hard in the cold cave air. Cassandra looked up at Bruce with an expression of pure docility, dark eyes wide with girlish innocence, black hair flowing freely down to her shoulders. And as he stared down at her, it occurred to Bruce that she was the most beautiful thing he’d ever seen. That’s why he felt so torn about what he was about to do to her. But at the same time, that’s why he knew that he had to do it. That he had no choice. “I’m sure,” replied Cassandra. “I want this. I need this.” Bruce nodded slowly. There was no use arguing, not when both of them wanted it so badly. When he spoke next, the gentle, caring tone he had been using slipped away, replaced by the voice that gave the criminals of Gotham nightmares. The voice Bruce used to intimidate. To control. “Turn around,” he ordered, and the girl did as he said without hesitation. The older man ran one strong hand down her soft, smooth back, stopping at the curve of her buttocks, giving it a little pinch that made Cassandra yelp, then giggle. “This is going to sting,” warmed Bruce, taking the large syringe from a counter at his side. It was filled with a clear pink liquid, tipped with a long thin needle. Slowly, carefully, he pushed the needle into the flesh of her lower ass. Cassandra whimpered, whether in pain or pleasure Bruce could not tell. When the syringe was fully in, Bruce pressed down on the plunger, squirting the pink liquid deep into her veins. The girl closed her eyes, mouth open, letting out little gasps and sighs as the concoction flowed through her blood. When Bruce was done, he pulled the syringe out of her, placing it back on the counter. Seized by a sudden impulse, he wrapped his arms around Cassandra, one holding her stomach, the other wrapped around her neck. His cock, hard from the contact, pressed against her backside. “How do you feel?” Bruce whispered in her ear, and Cassandra shivered, eyes still closed. “I feel... good. R-really good.” Bruce smiled proudly. It had been no easy task developing the formula, combining Pamela Isley’s pheromones with Jarvis Tetch’s brainwashing technology and even a touch of Joker Venom. The process had taken both money and patience. Luckily, Bruce had both. And it was clear now that it had been worth it. “The mental changes will come first,” explained Bruce, as Cassandra trembled in his arms. “You’ll find it hard to think. Even the most basic thoughts will be stressful, as your brain becomes more and more fuzzy. Once the chemicals take full affect, there will be no going back. No returning to the way you were. If you have doubts, any doubts at all- tell me now, while you still can. We can still reverse the process-“ Cassandra shook her head almost violently. “No! No... it feels so good. So... amazing. Don’t stop it. Please, don’t stop it!” Bruce could tell she was close to crying, so he spoke soothingly, trying to calm her down. “I won’t. Not if you don’t want me to. Just remember... the process won’t stop with your mind. Your body too will be transformed. The person you once were will be gone.” And when she heard that, Cassandra smiled. “Good. Good.” Pity filled Bruce’s heart, replacing the arousal that had been building. Cassandra Cain, raised from birth to be a living weapon, made into a murderer at the age of eight, raised by a father taught her nothing but violence and death- No wonder she wanted to forget. No wonder she wanted to lose herself to the drug’s haze. No wonder she didn’t want to be herself anymore. Cassandra’s legs were wobbling, her whole body growing limp. Bruce held her up, arms tight around her, and he planted a series of kisses on the back of her neck, on her cheek, on her collarbone. She groaned, her voice growing weaker and weaker, and moments before sleep took her, she mumbled something so quietly Bruce had to lean in to hear it. “Th-Thank... Thank you...” Then she was unconscious, and Bruce hefted her up into the air in a bridal carry, carrying over to the Batcave’s medical table, gently lowering her down onto it. The girl’s body was limp on the flat metal surface, her arms and legs sprawled out at strange angles like a rag doll. Cassandra’s eyes were rolled back in her head, showing the whites of her eyes, and her mouth hung open, a thin trickle of drool dripping down her chin. Helpless. Powerless. Lifeless. Bruce leaned down, slowly bending until his face was inches from hers. Their lips brushed together, and Bruce thought back to the stories his mother would read him when he was a baby. Snow White. Sleeping Beauty. But in reverse, the kiss not awakening the princess, instead drawing her deeper into her sleep. And Bruce was no handsome prince, rescuing the damsel in distress. He was the dragon who captured them in the first place. And with a kiss, I die Bruce watched as the seventeen year old girl slept in front of him, the chemicals inside her working hard to erase her mind and contort her body, turning her from a serious and silent soldier in the fight for justice into a brainless bimbo, a stupid slut with no thoughts besides how best to please her master, enlarging her breasts and her ass and her lips, making her his slave- And in that moment, Bruce knew what love was. Love was about protection. Love was about keeping each other safe. He had loved Barbara, and he had loved Jason. He had loved his parents. But he couldn’t keep them safe. He couldn’t keep any of them safe. But now it would be different. Bruce would be able to keep Cassandra safe. She would be his property, and she would be protected. She would be loved. And in return, Cassandra would keep Bruce safe. From the demons locked away deep within him. From the ghosts that haunted him whenever his eyes were closed. Because she loved him. And that was all that mattered. End Notes This was originally going to have multiple chapters, but I’ve decided I’m happy with it as it is. If people want me to continue, I will. Please drop_by_the_archive_and_comment to let the author know if you enjoyed their work!