“Mmnh…” Nanachi was somewhat aware that she had awoken. The young rabbit-like girl opened her eyes, and knew immediately that something was terribly wrong. Sure, it was going to be dark this far down into the Abyss, especially during night, but she should at least be able to see the void, that nebulous field of consciousnesses, the barely visible forcefield that made up the curse.
“Riko? Reg? Where are you guys, haaa~?” Nanachi called into the darkness. There was no reply. Fear creeping in now, Nanachi moved to get up, but…
“Hnn? W-what is this...?” She couldn't move her bushy, furred arms, her squat fuzzy legs, or her undeniably cute tail in the slightest. From a vague sense of self she could tell that she was on her back, with her paws stuck in some kind of padded shackles. There was no give to the sturdy cuffs, she couldn't even get it to rattle when she shook her legs. Her legs were kept spread and straight, with a similar cuff just below each knee. Only her tiny toes could wiggle a bit. Her arms were bent out and up, hands just inches from her ears, a strap on each forearm by her elbow. Most worryingly, even though she couldn't see herself, she knew her tail was kept down. She wasn't born with it, but she was still a bit shy about the underside of her fluffy tail, especially closer to the base. She knew that even with her baggy pants, this was now visible to anyway at the foot of the table she was strapped to.
Her first thought was Bondrewd, that irredeemable bastard they'd only barely escaped from. Nanachi, Reg, and Riko had labored over a foolproof plan to kill him that would have been overkill for any normal delver. All they accomplished was taking out a single one of the bodies that that demon can move his consciousness through with the use of a powerful and rare artifact. After the battle, though, he'd let them pass deeper into the abyss.
Nanachi was only barely able to choke back a scream when something brushed the tip of her left ear.
“How wonderful. Truly wonderful! It would seem you found your way back to me.”
A stone-cold chill of terror spread from heart and out through her entire body. Bondrewd, the soulless, unkillable bastard himself had somehow kidnapped her right out from under Reg and Riko while they all slept. She gathered as much nerve as she could given her situation.
“You asshole... How did you reach us…?” Nanachi asked, managing little more than a wimper.
“Oh, the Zoaholic has a magnificent range. I was easily able to track you down.”
Some small ember of hope lingered deep within Nanachi's small and bound frame. “They'll be coming to destroy you again, you know!” She didn't believe that any of this would actually intimidate him enough to leave her alone, but she felt cornered, backed up into a corner physically and emotionally, and the was all she could do to fight back. “Reg’s power was recharged, and we know where the Zoaholic is! We know you can't move it! Back off! Please-!”
She instantly regretted begging, and felt horribly weak and vulnerable now that she’d let slip how terrified she was. 
“Oh. Oh! That would be wonderful! I would be so pleased to see them become strong enough to overcome the burden of two layers!”
The last of Nanachi's brave hope was extinguished. Two layers...? What the hell!? There's no way he could've taken me more than a hundred feet up without…! 
She refused to think about it and further. She knew where that thought led, and she'd puke at the realization that he’d used those… them… on her.
“Ah! I can tell by that twitching tummy of yours that you realize how impressive it would be if your friends made it here!” He gently prodded her stomach. She barely bit back a cry, and tried again to pull against her restraints.
“Oh, that's right!” Bondrewd said, poking her in the stomach again, “That brings me to why you're here today. You see, every one of my gifted have run off, or perished. I needed more data on this wonderful body of yours.”
He was now steadily poking her in the tummy and sides, and she hated it. Due to the blindfold, she couldn't anticipate when or where he’d poke her defenseless belly next. She hated that all she could do was twitch and squirm and try not to cry… and absolutely try not to laugh.
“Perhaps there have been changes to your nervous system that make you more sensitive to touch or dulled to pain. Maybe you've been granted an overactive adrenal system for a stronger fight-or-flight response! There are secrets yet held by your body that we need to get out of you! I'm sure you have no problem cooperating!”
“Nn-nnaah… Just go die. Leave me alone, I don't want this…!” Nanachi struggled against her bonds again, uselessly.
“Well, I can't say I didn't expect this. But it's okay! You'll get to help me with this critical research whether you want to or not! I'm sure you'll do great.” And with that, Nanachi felt him roughly grab her head, pressing her jaw closed. With no way to really oppose him, she settled for not having bitten her tongue accidentally. Then, she felt his hands replaced with something else. Firm, fitted perfectly to her head. Claustrophobia threatened to take over when she realized she been fully muzzled.
“Oh, don't worry about this little piece!” he patted her cheek, causing her to flinch hard, “this just helps us skip all the useless begging, pleading, and screaming! That'll only get in the way of my tests.”
“Now then…” he said, and Nanachi felt the table under her shift, her head and legs dropped just a few inches, but the middle of the table stayed put, stretching her torso out, pushing her right into Bondrewd’s horrible, teasing fingers. He patted her tummy, and she was grateful that at least this want a poke or anything.
“Now where do you think we should start? The arms?” He trailed his fingers down her arms from wrist to pit, leaving an uncomfortable ticklish itching behind that she absolutely couldn't do anything about. “Keep going with your torso?” He lightly scratched his way down her sides and around to her navel. She felt her organs tie themselves in knots, and she shivered as much as she could in her restraints. “Maybe explore your adorable legs?” Here, he brushed his fingers from her navel, down….
There was no stopping it. She shuddered and screamed through the muzzle, only managing a pathetic whimper, as she felt him rub uninterrupted down her inner thigh to her paws. Nanachi realized at last that she was completely naked. Never in her life had she felt more humiliated, horribly vulnerable, totally exposed than now. Bondrewd noticed.
“Of course you'd be left bare for testing~!” He sounded like he was sincerely trying to comfort her. “I wouldn't be able to get to every single intimate part of you if I allowed you clothing. Now, I believe we've found a good starting point for this intriguing project!” 
Nanachi felt him press one finger into the center of each of her undefended footpaws. She gave one last effort into pleading with him. All she could get out was mumbled “Mm-mmm!” while shaking her head blindly.
“I wonder if you'll be able to handle this decently well…” he pondered aloud for her benefit, “I hope not.”
With that, he started to scratch small circles in the center of her paws, from just under her toes, along the outside of her sole, across the balls of her feet, and back up her furry arches. Already, Nanachi knew she was screwed. As much as she hated him and hated this situation and HATED being naked and restrained, there was nothing she could do to escape the tickling. She held on just barely, somehow not laughing but breathing very heavily.
Bondrewd did not relent however. He reversed the pattern on one paw, keeping them out of sync. There was a small hiccup in Nanachi's breathing rhythm, and she struggled to regain her composure even though she couldn't predict the patterns anymore. He added another finger to each paw and changed his pattern up again, sensing her begin to crack. 'So soon. Wonderful!'
Nanachi's will was failing rapidly. She actually already knew it was completely useless to even try and hold out. There was a very specific reason why she didn't like Reg rubbing her, his metal fingers caressing and exploring her fur. She knew she was extremely ticklish. In a word, she was fucked. Still, the sooner she gave in to the torturous sensations crawling across her paws, the more she knew that Bondrewd would believe that she had become a willing subject.
“A surprisingly strong reaction so early! Let's explore in a bit finer detail…” She felt his hands mercifully leave her paws, but before she could start trying to regain her breath, another sensation shocked a stream of giggles out of her before she knew what she was doing. What felt like tiny but powerful streams of water were now pointed at her two big toes! She couldn't even think to stop giggling until she got her paws away from that cruel device, but no matter how she twitched and pulled and kicked, those streams remained trained on her. They switched to her second toes and her giggling blew up into a steady laughter. Without anything else to do with the adrenaline rush from trying to escape, it all went into the one part of her that could move. Her lungs.
“Oh no, it's looking like you're far ahead of the curve on skin sensitivity. We've barely begun and you’re almost out of breath! You must be very brave to volunteer when you know the next twenty-four hours are going to be hell!”
WHAT? No, he couldn't! He can't do that, he can't tickle her like this for a whole fucking day! She knew she wouldn't survive! But still, even as she cringed in horror, the muffled laughter through her muzzle continued as the streams started to explore between her toes.
Bondrewd, an honest scientist, was recording a string of notes about the effect the “experiment” was having on the poor Nanachi. Gifted subject appears to have a more sensitive epidermis than the control. Exact measurements will be taken after warm up and calibration. Testing is set for 24 hours. Additional testing is being considered. 
Nanachi's will was fading rapidly. The assault on her paws continued relentlessly no matter how much she kicked and thrashed, and her laughter rose more and more every time she realized how helpless she was. The tickling was absolutely unbearable. The tickling would continue mercilessly. There was nothing to do but laugh harder.