the dorms(nighttime)

School has ended and the students of class 1-a are currently sleeping,all except two people,Izuku and izumi,the two siblings are in Izumi room,both of them fully naked and with Izumi sucking her brother cock,"Mmm you are being such a good slut Izumi"Izuku said and moaned as he complements Izumi for giving him a good blowjob,today was definitely not the best as the two vampires haven’t succeeded in changing many as Izumi only managed to bite 4 while Izuku only had bitten 5 including izumi,however Izuku hears his master telling him that while they could have done better,they didn’t failed either and that it is only the beginning.

As Izumi continued to suck Izuku cock,she feels herself changing as the bite that Izuku gave her this morning has made a comeback and she feels her changes,her tits,ass,hips and thighs increased in size,her skin becoming paler and her fangs and ears becoming sharper matching that of Izuku,her hair become darker and most notably she feels her muscles increasing with her also gaining a six pack and getting an Amazonian like body physique as she finishes her transformation,she then hears the master,her master welcoming her to the growing family.

Izuku climaxed,blasting his cum right into Izumi mouth and Izumi swallowed and made sure to not let a single drop of cum go to waste,"Hmmm,thanks for the meal,dear brother~"Izumi said,her voice more seductive and lustful then before,"glad you enjoyed,but we aren’t done yet"izuku said as he stroked his cock.

Izumi immediately knew what to do next and she went to sit on Izuku lap,her ass hot dogging his cock"go ahead Izuku and fill me with your seed~"Izumi said with a lewd smile,any of her previous nervousness and anxiety have completely vanished and replaced with the lustful confidence of a vampire and Izuku wastes no times and goes to fuck his sister dripping pussy.

Izumi hissed with joy at the immense pleasure she’s feeling as her master tells her about his plans,on turning every human into a vampire and the pleasure they would give to them all,it all makes her even more horny and hungry as she then gives her brother a deep kiss and begins to put her longer tongue to good use and exploring his mouth with him returning the gesture by Doing the same and with him not stopping to fuck his sister pussy for a second and a few minutes later,he begins to feel the darkness and hunger inside him growing as he knows he about to reach the final stage.

Izuku goes limp for a few moments with his cock still inside Izumi and with Izumi still kissing Izuku and bouncing on his cock,not bothered by her brother going still as she knows exactly what about to happen as Izuku begins to change for the last time as his skin becomes a deadly white pale and his hair become pitch black,his muscles increase in size once more as well as his cock as it enlarged and grows longer deep inside Izumi which causes great pleasure and moans from her as she sees izuku eyes glow an ominous crimson red and his black claws grow longer and sharper as his transformation is finished and he is now a fully fledged vampire with his master voice louder than ever in his head and his soul has been completely gone and replaced by darkness.

Izumi looked at Izuku with absolute lust upon seeing her brother fully changing and she can’t even say anything as Izuku immediately thrusts his newly massive cock deeper inside Izumi causing Izumi to hiss and moan loudly as Izuku thrusts with immense force onto her and in just moments he releases his massive load inside Izumi which causes Izumi to orgasm herself but neither of them are remotely done as they are still oh so horny as Izuku continues to fuck Izumi moreso like a beast,both of them not even thinking about stopping anytime soon.