It wasn't that she enjoyed doing it to herself.
Quite the opposite; she hated when the need arose within her.
But it wasn't something she could just stop. The need for it curled deep inside, lying dormant until it erupted inside of her. It entwined itself within her insides, digging a deep, deep, hole within her chest.
It filled her lungs until she could barely move from the weight of it all. Couldn't breathe, either; it truly was like drowning.
She had that feeling all through her time in the camp. Sometimes it dragged itself behind her, other times it was her shadow, waning throughout the day, but always there. Her fraternal twin. Always by her side.
She didn't need to satiate the need in the camp. The labor brought about plenty of injuries itself. Bruises and scrapes, sometimes entire fingernails ripped off, as well as scales. Nothing that would cause serious injury, but enough to sting. If she truly craved something serious, she could've goaded the guards until they assaulted her. But she didn't have a death wish.
There was one night where she had accidentally gone too far on herself.
She wasn't intending serious injury, much less suicide. As it turned out, there was a scale upon her neck that she shouldn't have pulled off and continued to pick at. There had been an artery nearby that her fingernails got close to. No matter what she did, dark blood continued oozing from the wound, soaking her rags. It was bad enough that other prisoners took notice and began to fret.
She ended up spending three days laying in a corner in "recovery", after someone had gotten a Breen guard, who had given them a dermal regenerator to use on her. It did nothing to replenish her blood, so another few weeks were spent with Ziyal feeling quite weak and lightheaded, though she eventually recovered.
Funnily enough, at the moment of removing the scale and digging into the soft flesh, she hadn't experienced any real pain. She felt the roughness of the scale, the softness of her body, and the wet blood, but there was no pain. Afterwards, she had been overwhelmed with pain, but not in the moment of the injury.
She took care after that to keep from injuring herself in that area, sticking to more minor abrasions, or at least ones that wouldn't endanger her.
(Although, there was a part of her that craved it again and again. It craved the way the blood poured out of her despite all efforts to stop it. It craved the way her body felt so light that it could float away. Float all the way back to her father, whom everyone said had abandoned her and would kill her. Float back to his warm touch and whispered words of love in the night.)
Upon leaving the camp and returning to her father, the feeling was suppressed. For a little while.
It helped that she was constantly under her father's watchful eye on Cardassia. Any signs of her previous injuries were believed to be a product of her time as a prisoner, none thought by her father to be self-inflicted in any way, but any signs of a new injury were met with harsh scrutiny, which made it hard to continue without his knowledge.
She scarcely had a moment alone when they were together on Cardassia. It made sense, they had been separated for such a long period of time, so it was only natural for him to stick by her side like glue. And it made sense for her to allow it, because he was her father and she needed it.
Ziyal wasn't entirely sure if her father knew what she had done to herself when she was held prisoner. She was certain at first that he must've had some sort of inkling of it, but she quickly realized that he was rather dense when it came to that sort of thing. Loving, but dense, particularly with the women in his life.
Had he always been that way, or had the loss of Bajor made him duller? Ziyal had been far too young to understand what his emotional intelligence was like prior to the Cardassian withdrawal. Perhaps he'd always been like that, she was just too young to have seen it, to have seen him as anything but her father, her hero.
She really had missed him when she was in the camp. No matter what anyone said, she knew that he loved her and would come back for her eventually. It wasn't enough to fill the ever-growing void within her chest, but it was enough to continue on everyday.
(But she couldn't get rid of the image in her mind of the look in his eyes as he aimed the rifle at her while Kira told him not to.)
Ziyal truly was grateful for his return to her, and felt intense guilt whenever she thought of the fact that his wife left and his own mother disowned him. She didn't feel that her existence was enough to warrant all that, but Cardassian society was a mystery to her, and it was likely something she'd always be an outsider to.
It wasn't until they were on the Groumall that Ziyal had any time where she was truly and utterly alone.
It was surprisingly easy to find the implements she needed-
Who would notice if a small knife went missing from the kitchen? And who would know that she had a few less scales on her left thigh? No one, that was certain. The knife was safely kept in a small compartment in the wall next to her bed, and no one would see her in such a state of undress that her legs would show that much, her father made sure of it.
The knife kept her placated for a while. It was easy and simple. She didn't even need to use it sometimes, she was able to pry off some of the scales with her fingernails. Beneath, the flesh was pale and soft, and far too sensitive to the touch. Her dark blood would bubble up out of the wounds until it came out and ran down her legs. The rivers would split off between her scales that she hadn't pulled off, and it was a pain to clean between each one, but it was worth it. She needed the pain, she needed to know that she was alive and her body was real.
But how long would it be before she went back to needing more and more?
Would she always end up craving more? More pain, more blood?
(Perhaps she should've been left in the camp, she would've gotten more than a fair share of pain and spilled blood.)
She would do anything, if it meant she could touch her skin and be reminded that she was real, that her pain was real. If it meant having to do more and more to keep that feeling, then so be it.
The knife sat in front of her, beckoning her closer. The scales on her legs had been taking longer and longer to grow back, she'd need to do it somewhere else.
The scales on her arms were right there-
And she always wore long sleeves anyways, so there would be no questions-
She was just doing what she needed to do. She didn't like it, but it was necessary to keep going, just like the food she ate and air she breathed.
Even if one day it would consume her entirely.