(Based in the other story, in this branch they don't get along and Hilda is more dominant)
Jeff thought of his older and annoying sister Hilda, it would be really strange to turn into her living pussy but that just excited him even more, so he was planning to slide his feet into her pussy while she was asleep.
Speaking of the devil, Hilda showed up in his room not even knocking the door. "What are you doing?" She approached him even further. "Playing some of your stupid games on your PC?" She giggled.
Jeff and Hilda didn't get along, since Hilda was the only child she received many gifts, but for her surprise one day her parents told her she was about to have a little brother, that didn't bother her until she realised that her parents started to care more about their new son, spoiling him even more than Hilda and giving him all the things he wanted.
Even so, things weren't different in the present, Hilda needed to work hard since her parents pushed her "fulfilling her role" as the older sister while they didn't say a thing to Jeff, all of that nonsense made Hilda develop a big hate to Jeff, many times wanting to get rid of him.
"Y-you weren't sleeping?" Jeff nervously asked.
"Uh, yeah, but an alarm woke me up and I only heard you since mom and dad aren't here for a week"
"Can you give me some personal space?" He was annoyed at that point.
"What do YOU know about that!" Hilda angrily asked, she approached the computer. "Wa-WAIT!" Jeff struggle trying to avoid his sister looking at it, but she was way stronger throwing Jeff to the floor. "Let's see what's this about, I did all my homework so I don't have anything better to do" she said as she read.
At first Hilda didn't believe what she was reading. "A computer that makes everything real? How dumb" she thought, but as she saw many details more her interest began to grow, being interested on the transformation part.
"Turning into someone else body part? God, you're so weird" she laughed at Jeff and his strange kinks, but deeply she had the same twisted fetishes as her brother. "So who's body part will you becom..." She kept reading and blushed, "my vagina!??"
Jeff still on the floor blushed and covered his face, "I-I-I can explain!"
Hilda thought about it, the idea actually excited her, even more thinking that she could get what she always wanted, getting rid of Jeff. "You know what little bro, don't worry."
Jeff removed his hands from his face, "r-really?"
"Yes..." She opened the the options Jeff set for the transformation and changed some of them matching her preferences.
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CHRONIVAC SETTINGS:
Target: Jeff Lawson ()
Host: Hilda Lawson ()
Function: Vagina
Shrunken on entry: Only if needed
Host sees target as normal: False
All else see target as normal: True
Can use bodily functions separately: True
Can detach at will: False
Will keep their senses: True
Duration: Permanent
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Jeff previously set the transformation's durations for a couple of hours, but his sister changed it to permanent in order to follow her evil plan. She pressed the ENTER button, noticing that nothing happened but feeling a little tingle in her crotch, she had the feeling that everything she read was true, Hilda smiled about to begin with everything.
She took off her pants and panties showing her trimmed pussy in front of her brother, "what are you waiting little bro~" she approached his paralyzed body, Jeff couldn't move as Hilda set that too.
Hilda sat on the floor spreading her legs facing her crotch to Jeff's feet, Jeff laying face down while Hilda shoved his feet inside her own pussy, they couldn't normally fit but due the Chronivac's power his feet could easily enter like it was an slimy and tight bag of flesh. The rest of his body was quickly sucked by Hilda's vagina until only his face was outside, during the process Hilda's reproductive system disappeared, uterus, ovaries, everything, with Jeff filling all the emptiness, even her vaginal lips, clit and pubic hairs were erased, now it wasn't a vagina anymore but more like a hole between Hilda's legs showing her brother's face. Jeff struggled feeling his entire body trapped inside his sister, this was what he was planning but wanted to do it more pleasurable from him, instead Hilda did some modifications to make it only pleasure for her.
"Oh god" Hilda left out a little moan before Jeff fully entered. "This... feels kinda weird" she rubbed her belly, even that outside she looked normal she could feel the entirety of Jeff filling her. "I can't feel pleasure right now since now my pussy and clit are gone, but I'm glad that I made this whole process feel good for me... But painful for you~"
"Painful? The only thing you did was shove me inside your horrible puss-" before Jeff finished he began to experience the changes, Hilda smiling feeling the pleasure return.
Jeff's body started to internally change ready to fill the spaces left inside Hilda, Jeff's legs began to shrink until he was a mere torso with only his head attached. Jeff's face and Hilda's body looked normal from the outside but the whole process was happening inside. Then Jeff's internal structure began to merge with Hilda's insides, his whole organs began to reshape themselves, the whole process was horrible for him, he tried to scream but apparently Hilda removed his vocal cords while his throat turned into a vaginal track leading to his stomach, which was transformed into Hilda's womb. Therefore a cervix formed in the womb's entrance. Next his lungs fused into a single fleshy recipient that would eventually be the bladder but was just connected to Jeff's mouth instead of both his nose and mouth, another but smaller hole formed inside his mouth that resulted into the urethra. His nose nervous connections morphed to give pleasure to Hilda, so his nose turned functionally into her clit. The rest of his organs disappeared turning into flesh filling the rest of Hilda's emptiness, Jeff could still be alive thanks to the Chronivac and getting all he needed to live from his big sis. The only remaining thing was Jeff's penis which immediately shrunk until it disappeared, while his ballsack separated and stretched, each one in opposite directions, at the end his testicles changed its shape to turn into ovaries, which now were connected to Hilda's womb, formerly Jeff's stomach. Jeff was finally a human vagina.
He tried wanted to cry but he couldn't, just expelling his sister's fluids from his mouth that replaced his saliva.
"Oh my~ look at that" Hilda said spreading her legs in front of a mirror, looking at her brother's head between her legs, she inserted two fingers and opened his mouth, which looked exactly like a vagina inside. "God you feel twice, no, more than three times the pleasure I felt with my previous pussy!" She inserted her fingers and masturbated.
The only thing Jeff could do was "fight" with his tongue, which contradictorily made Hilda feel better, stimulating her insides as she touched herself. "Mmmph.. oh~ don't stop" she kept going until she couldn't more, climaxing and squirting, expelling her stream of fluids from Jeff's mouth.
Hilda slowly stood up, smiling at the mirror looking at her constantly drooling vagina that was her brother. "We're going to have so much fun Jeffy~ or should I call you pussy, not that someone else besides me is going to remember you"
She typed on the Chronivac again, changing reality to make everyone forget about Jeff, and thinking Hilda's boy's head-shaped vagina was something completely normal.
Jeff tried to struggle but again he just drooled from his mouth as he couldn't even talk. "You can keep going~ it just feels better and better for my, so I'll recommend you to get used to this, don't forget the taste of my pee, menstrual blood and all the things I'll insert inside you! You'll know how to live as a pussy in no time" Hilda laughed walking through the room with just her crotch naked, she was excited thinking on what to do while her whole pleasure was her brother's suffering.