==Chapter 7, Doppelbanger (Cons, Incest)==

Gudao lay naked and spread-eagled across a mound of pillows that had been stacked against the headboard of the bed he shared with his sister. His arms and legs were bound in place, with enough slack that he wasn't in any particular discomfort, outside the fact that he was powerless to do anything about the raging erection between his legs. A simple cloth gag had been slid between his teeth and tied behind his head, loose enough to not be uncomfortable but tight enough to prevent coherent noise. On the floor next to the bed was an empty bottle of one of Da Vinci's more recent concoctions, bearing a label identifying it as 'Da Vinci's Super Virility Max!!!'. Minutes prior, while Gudako had been pressing the bottle to his lips Gudao had expressed misgivings about drinking the concoction, having heard that Da Vinci labeled this products strength by the number of exclamation points it had, that one staff member had already had a heart attack while helping to test the one exclamation point variant, and that he was pretty sure that this strength was explicitly made with servant's extraordinary durability and stamina in mind. Gudako had assured him that not only had that incident been with an early prototype, but that Da Vinci had assured her that they would need at minimum three exclamation points of strength to overcome the poison resistance they share from their contract with Mash. Gudao might have protested harder had he known that his sister would immediately scamper off after he had emptied the bottle, leaving him to suffer the effects in solitude. His dick felt almost painfully hard, felt like it was almost literally burning with need. When he wasn't focused on trying to wriggle out of the leather cuffs that bound him Gudao was intently focused on the door, trying to will his sister back through that door so that she could take care of what she started.

Gudao was so intently focused on willing his sister through that door that he thought he had somehow fractured reality when the door finally opened and two instances of his twin sister walked through. The two girls walked to the center of the room, directly at the foot of the bed, and turned to face Gudao, cocking their heads with a wry smile in a perfect mirror of each other. The two Gudakos were exactly the same, save that one had her side pony tail on her left, as was her usual style, while the other had hers on the right.

The two Gudakos enjoyed Gudao's dumbfounded expression for a few moments before turning to face each other and joining their lips in an exaggerated open mouthed kiss. As their tongues wrestled their hands began to wander towards the buckles on each other's uniform. Dexterous hands pulled on belts, zippers, and cloth. Jackets, shirts, and skirts gradually accumulated on the ground. All of this while the intense make out remained unbroken. Soon the pair wore only their underwear, tights, and boots. The pair broke apart, first one, then the other sitting on the edge of the bed while the other pulled off her boots and tights. Now the pair only wore their matching black underwear, of a simple yet sexy design.

The two Gudakos each approached a different side of the bed and started to crawl onto it. Gudao's eyes rapidly flitted from one pair of entrancingly dangling breasts to another. He had gotten quite worked up while he was in the room by himself, and after the show that had just been put on his mind was nearly overwhelmed with the desire for release. His muscles bulged as he strained against his bonds to no avail. He was beyond rock hard, his cock already leaking precum, only the slightest stimulation away from blowing.

The two Gudakos bent their heads in unison, extending tongues reaching towards the throbbing tower. Somehow, through the incredible fog of lust assaulting his brain, Gudao noticed that the left-tailed Gudako hesitated slightly before her tongue made contact. Any further thoughts on the matter were pushed to the furthest reaches of his mind as the two girls dragged their tongues up his shaft, collecting the liquid that had already leaked from it.

They hadn't even finished the first lap before Gudao's lust began to erupt. The two girls did their best to keep licking as Gudao's hips bucked, semen spurting everywhere, landing all over the bed, his lower body, and the faces of his twin, twin sisters. The orgasm was easily the most powerful one Gudao had ever experienced, and with his dick not showing even the faintest hint of beginning to falter it promised to only be the first of many. Gudao briefly recalled the rumored heart attack and prayed Da Vinci had prescribed the right dosage. The self proclaimed 'genius' was quite the trial-and-error kind of inventor.

The two Gudakos continued their efforts undeterred, expertly lathing their tongues over Gudao's stiff member for a couple more minutes until his hips began to once more shudder in orgasm. This time the two girls did their best to catch as much of their brother's cum in their mouths as possible, swapping to licking up the loose mess on his lower body as soon as the torrent ceased. Once they had collected their prize the two Gudakos smashed their lips together, their sloppy kiss dripping cum down their chins where it remained for mere moments before it was licked back up again. As their tongues wrestled their hands drifted to each others backs, unhooking their bras which were then pulled off and tossed aside, leaving the two pairs of breasts gloriously bare. After a long while they broke off the kiss, turned to Gudao, and showed off their mouthfuls before theatrically swallowing.

Next the two Gudakos one at a time slid each others panties off. The left-tailed Gudako lined herself up and unceremoniously dropped her hips, sinking Gudao's shaft into her welcoming folds and immediately beginning to ride him. The right-tailed Gudako straddled Gudao's chest, removing his gag and immediately engaging him in a heavy kiss. As the left-tailed Gudako let out her first loud cries of orgasm the right-tailed one broke off the kiss and straddled her brother's face. Gudao immediately got to work, muscle memory carrying him through his task as the left-tailed Gudako's pussy did its best to drive all conscious through from him by coaxing out his third load.

An orgasm each for Gudao and left-tailed Gudako and two for right-tailed Gudako later it was time for a reconfiguration. Gudao was unbound from the bed, left-tailed Gudako took the spot he had occupied leaning against the pillows, and right-tailed Gudako dove between her thighs. As his one twin did her best to extracted the prize he had just spent time depositing in the other, Gudao took up position behind her and slid his still hard dick home. He fucked her hard doggy style, watching the back of her head bob and watching her copy's face contort in pleasure. He slid his hand up along her back, sliding it into her hair and grabbing a fistful at the base of her skull. He shoved her face deeper into her twin's pussy, eliciting a moan from the latter. The three of them came at least twice more each before changing positions. Not long after they had all lost count of their orgasms, and not long after that how many configurations they had taken.

Hours later Gudao was lying flat on his back. left-tailed Gudako was riding him cowgirl, Gudao's dick in her ass. Right-tailed Gudako was pressed up against her from behind, one hand fondling her twin's breast while the other stimulated her clit with a small vibrating rotor. Left-tailed Gudako leaned her head back on her twin's shoulder, her tongue lolling from her mouth and her free tit bouncing alluringly as she shuddered in ecstasy. Gudao put his hands on her hips, keeping her balanced as she rode out her orgasm. When her erratic motions subsided and she resumed her rhythm Gudao's hands began to wander. His fingers traced up up her sides, the smooth skin shiny with sweat and sexual fluids. One hand stopped briefly on a breast, squeezing lightly, feeling the heft and playing with the stiff nipple, but with the other breast already occupied both hands kept moving upward.

Gudao's hands came to rest on her neck, holding her loosely with little force. When they did the left-tailed Gudako eyes swung to meed Gudao's, the gleam in them telling Gudao exactly what she wanted him to do. Gudako squeezed down, lightly at first but growing stronger. Gudako's hips started to swing faster as her face began to flush. They were interrupted however by a hand from the right-tailed Gudako. At first Gudao thought she was trying to stop him, but then she handed him one end of a wire garrote and he understood. Together the twins looped the garrote around their third's neck, giving her a brief respite to catch her breath, then together they pulled the wire taut. The left-tailed Gudako shifted her weight slightly and moved her hand from her brother's chest to between her legs, intending to pleasure herself as she was choked. It didn't remain their long however, the right-tailed Gudako grabbing her wrist and moving the hand between her own legs. Gudao used his free hand to grab and hold the left-tailed Gudako's last free hand when she tried to use it instead. Frantically she sped up the moving of her hips, desperately seeking pleasure as her face began to purple. A minute or so later, when her movements began to slow and it seemed she might not make it, the right-tailed Gudako used her free hand to press the rotor back to her asphyxiating doppelganger's clit. Moments later her body began shuddering violently as the combined throes of death and orgasm wracked her body. Only lagging slightly behind, her fingers and ass brought both her twins to their respective heights as well. As the pleasure coursed through them the twins fought to maintain the garrote wound around the neck of their extraneous third, somehow managing it as Gudao's pleasure emptied into her bowels and Gudako's squirted over her fingers.

Finally the trio came down from the respective highs, one falling a much greater distance than the other two. After a moment of rest where white knuckles never relaxed their grip, the surviving twins disentangled themselves from the body and laid it gently on the bed. The body's finger and toes had begun to glow a faint gold, but perhaps more interesting was the pattern that had begun to appear on its skin. The twins watched in fascination as an image of a dragon resolved itself on the dead Gudako's right shoulder, its long body twisting itself along her arms and legs. The dragon's tail ended within a pattern of roses that resolved on her left shoulder, running down across her torso and across both thighs. The twins watched as the body's red hair faded to black and lengthened, watched the shoulders broaden and the breasts flatten and tighten into taut muscles. The shimmering gold continued to encroach along the body's arm's and legs, dissolving them even as they reverted to their familiar shape. A couple minutes later the twins watched as Yan Qing's body crumbled and faded away completely, leaving the bed empty.

Gudao turned to face his twin, opening his mouth to say something. Instead he found himself being forcefully shoved backwards onto the bed. His sister straddled him, unceremoniously dropping her hips on his incredibly still hard cock. Gudao moaned in mixed pleasure and discomfort as his sister continued to wring his abused dick for everything it had.

...

A few more hours later the concoction had finally run its course. Gudako lay spread out on the bed, her chest rising and falling with heavy breaths. Her brother lay crumpled next to her, wheezing and coughing weakly. As long minutes passed Gudako's breathing slowed until it was a normal relaxed cadence. As even longer minutes passed Gudao's breathing gradually found a regular, if strained, pattern. Gudako helped gently turn her brother over and get him leaning against the pillows.

"Next time- *heurkk* next time maybe we give the two exclamation mark one a try." Gudao hoarsely choked out around a cough.

"Next time's gonna be two of you and one of me, so it should be around a third as much work for you. Two might be right, if it works at all, we'll have to ask Da Vinci." Gudako replied.

"A third? Shouldn't it be a quarter? I had to satisfy two of you today and would only have half of one next time." Gudao replied.

"Yan tapped out halfway through and I could still go a couple rounds, maybe I should say you'll have half as much work." Gudako replied, grinning and lightly flicking Gudao's limp dick.

Gudao didn't think the math really worked out that way, but he was too tired to think and knew she was just teasing him anyway. He grunted noncommittally and limply snuggled closer to his sister. Gudako noticed his struggles and closed the distance herself. She started lazily tracing a finger along her brother's chest.

"I really wanted Yan Qing to shapeshift himself a dick so you two could dp me, but that would have ruined the illusion. Something for another time I guess. Da Vinci said she's making progress on her futa potion, so maybe soon I'll be able to join in the fun and we could keep the illusion going at the same time. The three of us will have to gangbang Mash when we get a chance." Gudako rambled.

Gudao's dick visibly twitched, but even this evocative imagery wasn't enough to rouse it after the metaphorical ultra marathon it had just finished. Instead he just hugged his sister closer as the fatigue finally closed in on his mind and he drifted off to sleep. Gudako followed shortly after, the embracing pair enjoying vivid and erotic dreams.