I do not own Kingdom Hearts or any characters thereof, and will not be making any money off of them.
Nobodies can not feel fear. They can be startled, true, but in order to feel true terror, a heart is needed, and that is the thing that Nobodies lack. Of course, they're good at faking emotions, and as it has been mentioned before, if an emotion is faked often enough and long enough, it can almost seem real.
When Axel jumps out at her and yells "boo!", Xion shrieks and drops the piles of books that she was carrying. Then she glares at Axel. "That isn't funny, she mumbles, pressing her hand against the place where her heart would be beating like a drum, if she had one. He bends down and begins to help her pick up the books.
"No, it isn't funny." Axel looks down at the title of one book. "It's friggin' hilarious. What the hell are you reading?" He grabs another book, examining the cover.
"Roxas said that people with hearts read these books and then they feel… something." Xion's voice is defensive as she grabs for her book. She feels flustered, and while that isn't an emotion per se, it is close enough that she thinks that maybe… maybe hearts aren't needed for emotion. After all, if she can get flustered, maybe, if she practices enough, she can get sad or happy? Really happy, not pretend happy that takes more effort than she wants to put out, half the time.
"But you don't have a heart and can't feel anything." Axel takes another book. ""Scary Stories to Tell in the Dark"? Xion, if you wanna get scared, you should've just come to me." He's smirking.
"What?" Xion reaches up for her book, which he is holding up above her head.
"If you wanna get scared, just come to me." Axel wraps an arm around her shoulders and squeezes, gently. "I can scare you too, y'know."
"No you can't," Xion scoffs, walking slowly towards her room. "Scary things are things like… ghosts and monsters and vampires." Although she's seen all of those things, and none of them were particularly scary at the time. Maybe they're scarier in stories?
"Sure I can." Axel takes her hand. "Do you want me to show you?"
"Well… alright." Xion wants to feel something, and if she can feel genuine fear, maybe it'll be the gateway to other things, like love or happiness.
Axel opens up a dark portal. He squeezes her fingers and steps out of the portal into… thin air.
They are falling. Xion doesn't even realize that she's screaming until she hears the noise. The books have left her hands, blowing up in the wind, and they're falling down a huge hole. There are rock walls on either side of them and Xion doesn't feel anything, only knows that the ground is rushing up towards them. She feels warmth blossom between her legs, but she doesn't even notice because she is going to die, and even if she doesn't have a heart, she can dread, which might be as close to fear as she can get.
She is still screaming when they land back inside of the Castle That Never Was, albeit in Axel's bedroom. Axel opened a portal under them or something. Xion doesn't care, because she can still feel her body… falling, and she's shaking like a leaf. She's grasping at the front of Axel's coat, and she still screaming. She can still feel the wind whistling up her coat, even as she feels the solid stone under her feet.
Axel leans down and kisses her, hard, mashing his mouth against hers and swallowing her screams. He pulls her as close to him as he can, holding her tiny, shaking body against his own. He is smiling as he kisses her, that cocky smirk that Xion would hate, if she could.
Xion breaks the kiss and glares at him, blinking tears out of her eyes. "W-what was that?" She demands, glaring up at him. She's still shaking.
"That was fear." Axel's busy hands go to her zipper, yanking it down and grabbing her breast through her shirt. He presses his hand down against it, flat, because if she had a heart, it would be hammering against her ribs right now, under her breast. But there's nothing there, just the feel of her nipple getting hard under palm because even if her whole body is screaming "run!", her whole body is wound up tight as a spring and he's going to do what he can to make her feel as much as she can.
"That wasn't fear." Xion's hands are shaking as she clutches his coat, pressing her face into his chest. She feels his busy fingers moving into her coat, then down the front of her shirt, grabbing her breast roughly. She's panting, now, deep gulping breaths, and she's still shaking, still feels like her whole body won't move, but it's too full of energy, and she hates this, hates it with her not-heart. She clutches at him, hard, as his hand moves lower, between her legs, pressing the denim against her.
"Xion, did you wet you pants?" Axel's voice is laughing as he unbuttons her jeans, sliding his hand in, then into her panties.
"Shut up," Xion mumbles, her hands fisting his coat. Her whole body was tingling, and when his fingers brush over her clit, she shudders and takes another deep, gulping breath. She's sensitive, so sensitive, and with a start she realizes she's aroused. Really, really aroused. When did that happen? She whimpers, pressing her face into the front of his coat as his fingers stroke along her, feeling the tackiness from when she wet her pants and the wetness from her arousal.
"You did!" Axel presses down on her clit with his thumb, rotating it carefully. He feels her twitch under him, feels her shudder against him. She's still shaking all over, her knees still weak, and he almost absently grinds his erection against her hip as he slides a finger into her, feeling the slip-slide of her arousal under his fingers. "Do you like pissing yourself, Xion?" Axel begins to thrust his finger into her, then pulls it out and slides in deeper, curling it in such a way as to make her see sparks.
"Shut up," she mumbles again, wriggling against him and squeezing her legs together to get more friction. She can feel his erection pressing against the bone of her hip, feels it hot and thick. She's shaking like a leaf and she can feel the heat coiling in her belly, ready to snap. She's felt it before, of course. She's done this with Axel before, in many different ways, but this is different. She's shaking like a leaf and feels the beginnings of the sweet lightning start down her back, feels the familiar tightening and loosening of the muscles in her belly.
"No," Axel says back, pressing his face against her hair and jerks his hips against her, grinding his erection against her hipbone and shuddering as he gets closer. True, he wasn't scared by the fall the way Xion was, but it still sent a rush. He's full of prickling icy lightning, and he's close. He likes the way she feels close to him, shuddering and shaking, almost likes the way the stickiness between her legs, soaked into her jeans, is drying. "You felt fear. You felt something." He shudders, jerking against her as he comes, staining his boxers and dripping down his leg.
Xion feels it, and she shudders as well, pressing her face against him and squirming as she feels the heat in her belly… snap. She whimpers, then goes still, feeling the wetness soak into her already wet pants. She goes still and limp, then, sagging against him. "That w-w-wasn't funny," she mumbles against his chest.
"But now you've felt fear," Axel says quietly. "Do you still want a heart, Xion? Do you want to live with that for the rest of your life? You want to live where anything can hurt you, and every hurt is that painful?" He pulls his hand out of her panties, slowly, and lets go of her breast to rub her back. "Having a heart, every bit of everything hurts. Is that worth it?"
Xion stares up at him, panting. It takes a while for her to gather herself together. Finally, she takes a deep breath and looks him in the eye, blue on green. "Yes," she whispers. "It's worth every bit of it. Every bit of everything." She sighs and shudders, leaning against him. "It's worth it," she whispers as he presses a kiss to the top of her head.