Dan rubbed his chin. "So you think boys are evil, do you?"
Kat had gone pale, and when she opened her mouth to speak, her voice trembled weakly. "The fact you're even considering this cheap revenge proves to me that you're evil. It doesn't matter if boys are evil, Dan, because YOU are evil."
"See, you say that now," Dan said, with a shrug, "but I never ate a person. I never humiliated a family member. I never misused my power. I think maybe you need a change of perspective."
"Where's this headed," Mom said, suddenly sounding doubtful.
"Kat says I'm evil, Mom, but her actions have been much more evil than mine. Maybe we need to look at the world differently. Maybe you should turn me into Kat, and Kat into me."
Kat opened her mouth to protest, but she could only squeak. She put one hand over her mouth, and wrapped her other arm around her breasts.
Mom nodded slowly. "On the one hand, it seems fair. A straight reversal may be the fairest way to resolve this difference."
"But on the other hand?" Dan asked.
"On the other hand, if I swap you two, you'll be of age. A grown girl in our family already has her powers, which means you won't just get your sister's body. You'll get her abilities, and I don't want you to try and get revenge. Is that clear?"
Dan smiled and nodded.
"I'm not kidding, young man. If I catch you using your sister's powers on her like she used them on you, I'll turn you both back into babies and make you relearn everything from the ground up."
Kat finally found her voice. "You can NOT be thinking of giving my body and my powers to this... this BOY!"
Mom smiled. "Not just your body and your powers. Your whole life. You've shown great irresponsibility, so you need to prove to me that you deserve respect and ability. Now take off your clothes."
Kat got even paler, and her eyes grew wide. "What?"
"Take off your clothes. Dan has much bigger shoulders than you, and I don't want you destroying a perfectly good outfit when you transform." Mom turned on Dan. "You too. It might not rip your clothes, but you both need to face this as equals."
Dan eagerly stripped off his t-shirt and stepped out of his jeans. Kat took her time unbuttoning her dress, and tried to keep it wrapped around her so she didn't have to expose her modesty to her brother. "I mean it, Missy," Mom said through clenched teeth. "Take off your clothes."
Kat let her dress drop around her feet. The brother and sister stood facing each other stripped to only their underwear. Dan realized he had never seen his big sister in just her bra and panties. Still, he had to admit, she had a great figure. His sister was a sexy woman, and soon he would be, too. Dan worked hard to look her only in her eyes, because he didn't want the humiliation of getting hard for his own sister.
"Come on now, both of you," Mom said, sounding cross. "All of your clothes, both of you. If it's too awkward, turn your backs on each other."
Kat glared at her younger brother, who just smiled back. Finally, both of them nodded, and turned their backs on each other. Dan pushed his boxers off his hips, then dangled them off his ankle before kicking them onto the heap of his other clothes.
"Now get ready, both of you," Mom ordered. "This will be very uncomfortable."
Dan suddenly felt his spine stiffening. His ribs cracked and popped as his body reshaped itself into its new form. His thighs groaned as his legs got shorter, and his scalp felt like fire as his hair turned long, wavy, and feminine. He reached behind himself and felt his ass growing round, his hips growing feminine. Touching his chest, he felt his firm, masculine muscles turn into A-cups, then B-cups, before stopping at a size he'd never guessed at under Kat's loose-fitting dresses.
Last of all, he felt prickles and jolts of electricity as his penis retreated up into his balls, which flattened and spread into two tight labia. He was well and truly a girl. He ran his hand over his face: lips now full and soft, cheeks filled out, eyes large and far apart.
Then he felt something more. In his chest, right next to his heart, he felt a sudden throbbing warmth. It reached up to his brain, down into his pelvis, and out into his limbs. Aha! He had his sister's magic transforming power.
"That's it," Mom said, and stepped back, crossing her arms and appraising her work. "You've switched. But be aware: I'd sound stupid out in daily life, calling my daughter Dan and my son Kat. From now on your names are Danielle and Kenneth: Dani and Ken for short. Other than that, you've completely switched lives. Each of you has to live for the other until I'm sure you're both ready for the powers in your life. Now get dressed."
Dani turned, afraid at first that she wouldn't know how to put on a bra, but as soon as she picked up the pile of clothes that had been Kat's, and was now her own, she realized she knew everything she needed. How to put on a bra, how to wear panty liners, how to wash her girly bits, everything. She really now was her sister.
"All right," Mom said after watching them both get dressed. "I'll have my eyes on both of you. If I see either of you step out of line, rest assured, the punishment will be severe." With that, she turned on her heel and left the room.
Ken and Dani studied each other. Dani looked at her new brother through female eyes, and realized, Ken was good looking. Which meant she'd been good looking when she'd been Dan. Too bad she'd never known women found him attractive, Dani thought. I could've used that to my advantage.
Ken's thoughts ran a different direction. He looked dubiously at his big sister. "You have the power now," he said. "You're older, you have Mom and Dad's respect, and most important, you have my magic. What are you going to do with me?"
Dani reached out a hand and patted her brother on the shoulder. "You shouldn't have abused me," she said, grinning. "Because now..."