Marinette snatches the lamp and rubs it.
The genie appears from a cloud of smoke with a wave of her blonde ponytail.
"So you're the genie?" Marinette asks, her interest peaked.
"Yes, that's me!" Genie chirped.
Marinette looked at the other girls, with their bigger rumps and busts that always left her feeling inadequate before grinning and whispering into genie's ear.
Marinette chuckled with glee as the pink smoke engulfed her, and everyone saw her form change: a grow spurt putting her a foot taller than Samantha, her C cups ballooning out into a pair of DDD knockers that made Colin's jaw drop, Samantha huff, and Jamie sadly sigh. Her ass and muscles grew within the same dimensions, making Lucy jealous and Christina daunted. With the growth of her hair, the smoke blew away, revealing her porcelain white skin, slim waist, full lips, violet hair and amber eyes. Colin immediately recognized this as Camilla from Fire Emblem Fates.
"Well Master, what do you think?" Marinette said as she squashed her mammoth mammories against him, sending his shlong skyward.
"Bah-da-ba-da-ba...." Colin stunnedly stammered.
"I knew you would..." Marinette said as she took her master into the bedroom as the others looked on in shock.
'Good, now they get to feel as inadequate as I have for this whole time.' Marinette thought, 'Although I will admit what I've done to Christina was a tad unfair. She hasn't done me much wrong, and Jamie's... Jamie. I'll make it up to them... as their new misstress.'
As she thrusted up and down on Colin's member, she planned out the use of her new gift: you see, now when she... did it, she could affect people. For Colin, it meant more sexual endurance and a healthier body, as his fat reduced itself and muscle began forming. As for girls, it could convert ladies outside the harem or in it into more submissive girls who loved their misstress as much as their master, and become "upgraded" on top of it. As someone who looked through Colin's internet history after he... errr... "warmed up", she knew Mrs. Aran wasn't the only fictional girl who could catch his eye.
'Ohhhh, I have plans... hehe, yes I do.' Marinette smiled as she rode her master even harder. She'd later emerge soaked in jizz to declare herself Colin's new lead girl, much to Samantha's displeasure. That declaration is what set Marinette's plan into motion.