A gradual strip and enslavement.

"Whenever Monkey D. Luffy snaps his fingers around Kaya, she will remove an article of clothing, confused as to why she can't resist the urge, but not being upset about it. If he does so when she is already naked, she will be compelled to do a sexual act for him. These acts will start minor, but each following one as a result of a finger snap will get more and more drastic. And each one will cause the Jolly Roger of the Straw Hat Pirates to start to form on the small of her back. The more defined it becomes, the more submissive to Luffy she will become without a finger snap. Once she actually fucks him, it will completely form, and make her his sexual ****, though she will retain all other personality traits besides what would conflict with that, and she will treat him the same outside of sex."

Having finished writing that, Luffy quickly stowed the Note as Kaya returned with the bandages. "Now hold still while I finish up," she admonished him.

"Yes Ma'am," he grinned, snapping his fingers, making her pause, and reach up to her blouse, blushing as she unbuttoned it, each undone button revealing a bit more cleavage, her bra getting exposed as a simple cotton white one. Luffy sniggered as he asked, "What are you doing?"

"I'm... Not sure," she admitted as she shrugged her blouse off, still blushing, but mostly unbothered by her lack of control of the action as she dropped it.