Lina knew Rylai wouldn't be in her tent when she sneaked inside. Her sister was far more diligent in her study of magic than she was, so she would be in the library at this hour. A perfect time to look around, fumble with Rylai's things and play her a prank like good old times. It had been a while since they had last seen each other, so she thought she would prepare a little surprise for her. Checking Rylai's belongings didn't yield much though, her sister only had boring books and trinkets, nothing she could tamper with. "How am I supposed to make something blow up in her face when all she has is this? I guess I could always use her blink dagger to appear out of nowhere, but that's so cliché..." Playing with the dagger in her hands, she inspected the runes on it. They weren't the usual ones, and she couldn't quite figure out what they were for until she remembered what Tresdin had talked about the last time they went out together. "But why would Rylai have something like this? She's so prude..." Thinking about this, she realized she had found exactly what she was looking for, something to tease her sister with. She decided she would confront her sister when she came back to see her reaction.

When Rylai came back, she went to her tent to drop off her study books. Instead of finding her things how she had left them, she found her sister Lina lying on her bed, a smile across her face.

-The little pervert is finally back!
-What are you doing here? You come here unannounced, make a mess of my things and insult me, so you better have a good reason.
-I figured you would enjoy a visit from your sister. It's been a while and I thought it would be great to get together for some sisterly bonding.

-Fine. But calling me a pervert is not the best way to make me enjoy your visit. I don't even know why you would call me that. 

-Really? Then why do you have this?

 Lina took the dagger that was beside her, showing her find to her sister, enjoying the sudden crimson of her cheeks.

-Th-that's not what you think! And that's none of your business anyway!
-We both know what it is, sister. Why would you have something like that if you don't use it? 
-I... Alright, I used it, but only with good intentions. I went in that other world in acity to study the little people, and I even helped them. They were really happy I came so I went a few times when I had time, that's all.
-I should have guessed it would be that. It's always so boring with you. Oh, but I know what we should do together! This is perfect place to take some time off together.

 Getting up, she grabbed her sister's hand before she had time to react and she activated the blink dagger, which sent both of them to the last place Rylai went.

The city was a large and prosperous metropolis. It had grown a lot in the last few months, thanks to the help of a blonde woman who came a few times. She helped them dig for a new subway, she brought fresh water using her ice spells and shaped the land to make it easier to build. When the two sisters appeared, no one was afraid, but they were a bit surprised. The blonde woman was taller than she was last time she came, and she was with an even taller redheaded woman. They were both beautiful young women of similar build, curvy but thin.

Lina was surprised, too. When they arrived in the city, she noticed her sister was smaller than she was - more than usual. She was a full head taller and more, her sister's head only reaching the middle of her torso.  She also noticed her sister had the same surprised looked.
-What's up shorty? Something not like you expected?
-This is strange... and interesting. I wasn't this tall when I was alone, and you're taller than me. My guess would be that the height depends of the user, or the will of the user activating the dagger. I was smaller because I came to help, and Tresdin was bigger because she wanted to do... those terrible things. Which means... Sister! I won't let you harm them!

-Relax, relax! You don't have to jump to conclusions like that. Why don't you show me around, that way I know what to avoid. I promise I'll be careful.

Of course, she had no intention to be careful. As soon as Rylai had turned around and started carefully walking and showing the places to her sister, Lina's mischievous personality took over. Acting as she was unaware of what she was doing, she slowly and deliberately brought her naked feet down on people in the streets as she followed her sister. She tried not to crush them right away, preferring to feel them writhing against her feet. There was something exciting about feeling them struggle and die simply because she walked by, while also looking innocent to her sister. Wanting more, she acted as if she was losing balanced and planted her right foot down on a small building. By her estimate, she had probably killed a hundred people in that building just by being 'clumsy'. The feeling of the crumbling building under her feet was delightful : the crunchy feeling of her sole compacting the structure and its inhabitants into the ground was so satisfying, and it made her feel like a goddess to them. She killed them just by walking around a little bit carelessly, she was getting pretty excited about what she could do if she was really trying to crush them.

Her sister started turning around after hearing that. While Rylai was turning , Lina flicked her fingers behind her back, setting a nearby college on fire where Rylai was no longer looking

-Sister! Look at what you've done!

-Hey, you can't blame me for tripping. You should be watching where you are going, something caught on fire where you were going, you must have stepped on something yourself.

Looking back, Rylai saw the burning building and knew better than to blame herself for it.

-You bitch! I know you did it, and you know I can't just drop a huge block of ice here, it would just make everything worse! Fix it!

-I didn't do anything, and it's not like it's my problem; it's your city after all. Besides, it's not like I can make fire disappear. You'll just have to find something liquid to put on that. Eh, since there doesn't seem to be any water around, you could always piss on it.

She didn't think her sister, the pure maiden, would do that. To her surprise, her sister's frown turned into an uncomfortable expression as she opened her robe and removed her panties, slowly placing them in an unoccupied placed. 
"I'm sorry everyone, I have no choice. There's no way you can put out a fire this big. Please move out of the way for you sake."
Squatting in front of the college, she opened her legs and spread her vulva with her fingers. Aiming at the fire, she closed her eyes and let herself go, not wanting to see the devastation she would cause.
Lina watched intently her sister. Seeing her remove her clothes wasn't without effect on Lina : Rylai was beautiful and young with blond hair and a perfect silhouette, a pure and innocent woman. As if the sight of her body wasn't arousing enough, she squatted and exposed her intimate parts and started peeing in front of her. Lina quickly removed her clothes as well and revealed the stiff cock between her legs. She took it in one hand and stroked it as she enjoyed the show. She watched the torrent of yellow liquid fall and hit the fire, but she was more interested in what was happening around. Her sister was so shy she had closed her eyes, but that meant she wasn't aiming so well, so her urine was splashing everywhere around the college she was aiming at. People around the building were being washed away by the current. Some were being overwhelmed and were dragged under, drowning in it. She figured everyone inside must have been living a similar fate. Without enough time to react, they were stuck inside where most of her piss was landing, the rooms getting filled at a high rate. The people who weren't close to an exit were trying to swim their way out, but the level of urine quickly reached the ceiling. They clawed at the ceiling and walls as they fought for air, but all they could find was the foul, acid taste of Rylai's urine filling their mouths and forcing its way into their throats and lungs, choking and drowning them. The thought of a sweet innocent virgin murdering hundreds of people by peeing on them made her extremely hard and excited, she lusted for her sister's body now.

Rylai finally opened her eyes and saw that the fire was extinct, but she dared not look long enough, preferring to ignore the consequences of what she had done. She wanted to think she had helped them and saved their lives, when she was the one who was responsible for their doom. As she was about to get up, Lina came in front of her and pushed her on her back with saying a word. She spread Rylai's legs and placed herself between them, getting on her knees and readying herself to penetrate her. She quickly noticed that this would be a problem : her sister was still much smaller than her, it would be difficult to go inside her right away. Instead, she grabbed people from a nearby crowd and dropped them on her sister's sex, pushing some inside with a finger. "No Lina, you can't! You'll crush them!" Rylai tried to object, but her sister kept going. Placing her thumb on her sister's clitoris, she gently squeezed the people that were on it and slowly rubbed in a circular motion. The people squirming against her most sensitive part sent a shiver of ecstasy through Rylai's spine. Her sister kept going, watching her sister trying to fight the stimulation. She wanted to take care of them and protect them, so she had to resist giving in to the pleasure. Lina suddenly pressed harder with her thumb, the tiny bodies popping against the Maiden's clit, who was now gasping for air., unable to resist the stimulation of bodies breaking against her sex. Lowering herself to face her sister's sex, Lina licked her lips and got to work. Slowly working her tongue in her sister's folds, she coated the tiny people with her saliva, feeling them roll against her tongue. She enjoyed Rylai's taste, but rapidly found herself lusting for more. Grinding her tongue against the skin, some people were crushed and others were torn apart, sometimes surviving with fewer limbs. Lina didn't care how they ended up, as she had the chance to enjoy the most delightful flavor she had ever tasted. The fresh blood against the salty skin of the Maiden's moist sex mixed in with Rylai's juice was stimulating all of her most carnal desires, her rhythm accelerating as she wanted more of it.

 
Rylai was on the brink of orgasm. Her sister's tongue was doing wonders. The small beings were being ground and crushed against her sensitive flesh. As much as she didn't want to enjoy it, she found herself moaning with pleasure. While Lina was working her tongue from the outside, the people trapped in her were stimulating her from the inside. As waves of pleasure came and go, she clenched her vaginal muscles, forcing those inside to fight for their life. They struggled against the slippery walls of her vagina, fighting for air and trying not to get crushed. Individually, their struggle mattered little, but since they were all selfishly fighting for themselves, they only managed to pleasure her and doom themselves. Unable to control herself any longer, Rylai went over the edge, the walls of her vagina tightening around her little prisoners, crushing their pathetic bodies. In her excitement, she had given up on protecting them, their lives not mattering when their deaths lead to making even only one of her nerve endings happy. Moaning loudly, she yelled : "AH! This feeling is unbelievable! Your fucking lives are worthless compared to this!" Her orgasm kept going for a minute. Gradually, she came back to her senses, unsure of how she felt about what she had just done.

Lina didn't leave her sister to her thoughts for very long. While Rylai lay panting on the ground, she grabbed a few people and placed them on her cock, which was covered by her precum by now. Sticking them on it, she placed aligned herself with her sister and brought her dick to Rylay's sex. Slowly, she pushed in, her relatively small sister's vagina tightening against her cock. Her penis was already a big size and girth to someone her size, so it was massive to Rylai. The skin was stretching to let Lina's dick in, her fluids and the blood allowing it to slide in at all. Slowly, Lina inserted herself in until she hit the cervix, completely filling her sister, who couldn't accommodate her full length. "No matter," she thought "she's so fucking tight and I can feel her squeezing it. Besides, that's also why I got some helpers." The pain quickly brought Rylai back to her senses as Lina was inserting herself. Her body tried to fight it and squeeze out what was penetrating her, but it was only encouraging Lina to keep going until she hit the soft cervix. 
-Lina, you can't do this... you're going to kill those poor people inside me!
She didn't know if this was the right thing to do anymore. They made her feel so powerful and good that she wanted her sister to keep going and grind them inside her. She wanted to feel them struggle as the giantesses used them to have sex.
-Right, that's not what you were saying a minute ago when you were screaming in pleasure, you little pervert. Now it's my turn to cum and you're going to help me, whether you want to or not.
Having said that, she bent over Rylai, pinning her arms to the ground and holding her in place. Overpowering her was easy, since she was bigger than her; Rylai was hardly fighting back at this point. She slowly pulled herself out, enjoying the feeling of the tiny bodies against her hard cock, knowing they would eventually burst between her member and the soft walls of Rylai's vagina. Pushing in again faster than the first time, Rylai winced, her body tensing up as her sex was being forcefully stretched. Lina enjoyed dominating both her sister and the people of this city at the same time with her cock. Working herself to a rhythm, she focused her attention on the tiny bodies against her penis. She could feel them massaging it as they pushed against it, trying to resist the vagina squeezing around them. When she pushed in, some of them on her glans burst against her hard flesh as it spread her sister's inside, and the others got pushed deep into her sister and left there. When she pulled out, those near the corona of her glans were ground against it. Unable to resist the pleasuring sensations, her pumping got faster and harder. She didn't care killing those against her dick and using her sister as a fucktoy even if it hurt her; she felt the best orgasm of her life building up. A jolt of pleasure hit her as she came inside Rylai, her cum quickly filling her and drowning any survivor in the depth's of the blonde's cunt. She pulled out, grabbing her dick and aiming it at her sister's tits as she was still cumming, covering them with sperm.

Moving herself, she straddled her sister, her dick hanging above her."Clean it with your mouth." she told her sister, "Or would you like to let them do it?" she added, seeing the hesitation on Rylai's face. Rylai was curious to discover the taste, so she lifted her head and observed Lina's limp member. It was covered with cum and gore, and even soft it was still pretty large. Placing the tip in her mouth, she started to gently suck it. The taste was hard to describe, but she found it fairly good. Putting more of it in her mouth, she moved her tongue around and pressed her tongue on the bottom, squeezing everything left in her urethra. Taking it out, she went on to lick the base, her sister's cock on her face. Lina had a hard time believing her sister had never done that before. She couldn't contain herself as she watched her sister lustily licking her dick. She felt herself get erect at the sight of her cock lying on the Maiden's face. Hard again, she grabbed people from the crowds around and dropped them on her sister's breasts. Her sticky cum held most of them in place, but a lot fell in her cleavage, stuck between the massive mountains of flesh. Satisfied, Lina didn't lose any second and placed her cock between Rylai's tits, grabbing them with her hands and squeezing her cock with them. She pressed hard and fucked away, crushing everyone in her sister's cleavage, using them as lube. Killing them was so exciting that she felt her orgasm coming already. Panting, she addressed Rylai : "I'm about to cum, so you better catch everything with your mouth if you don't want this city covered in cum." Her sister barely had time to open her mouth that she came. Rylai's mouth wasn't big enough for the size of Lina's load, and she couldn't swallow fast enough. Lina's twitching cock kept spurting thick cum everywhere, covering the nearby streets and building. The luckiest people were those that only got stuck in it, most of them drowning from the tiniest amount, unable to cough out the warm  liquid since it was too thick.

Swallowing Lina's cum and watching her murder all those tiny people with her tits was certainly having an effect on Rylai. Without Lina even asking, she raised herself and sucked her cock, hungrily licking off the bodies off of it. "This was a great idea after all Lina. We've never been this close. Let's go again." she said while looking her sister in the eyes. "You say that like I never have good ideas. Come on, turn around. We'll take them for a ride." answered Lina with a smirk. Rylai obeyed, getting to her hands and knees. Looking around, Lina gathered a few buses. Taking one of Rylai's butt cheeks in her hands, she moved it aside and poured the contents of the vehicles one by one in the Maiden's crack. After, she grabbed her other cheek, placing her thumbs on Rylai's anus and the tip of her cock between her ass cheek. Slowly, she slid her penis between the Maiden's cheeks, pushing the tiny beings toward her asshole until they reached it. Inserting her two thumbs in it, she stretched Rylai's anus, making the tiny people fall inside her sister. Letting go, she sealed them inside her sister's body. With one hand, she grabbed her sister's hip and with the other she pushed her upper back, pressing her sister's face and shoulders to the ground. As her sister pinned her, Rylai could feel the building crumbling under her, her breasts crushing thousands of people under their weight. Her sensitive and hard nipples felt every single tiny body bursting against them. Her face was close to a crowd and she could see them panic. She was panting now, her hot and humid breath washing over them, smelling of cum. Lina placed the tip of her penis in front of Rylai's anus and pushed in. The Maiden let out a loud moan out of pain and pleasure which made everyone in front of her mouth cover their ears, the sound breaking their eardrums. She extended her tongue, picking up people from the crowd on her sticky tongue and pressed it on the roof of her mouth, savoring the aphrodisiac. Lina started pumping hard right away, the earth shaking around the two sisters. Rylai's asshole was even tighter than her cunt, Lina felt like it was trying to crush her dick. She was quickly brought to the brink of orgasm, and she started slamming her sister's ass hard, the ground shaking with every thrust. Buildings everywhere in the city crumbled, their foundations clearly not prepared for two giantesses passionately having sex. They came together, thinking of the tens of thousands of people dieing around and inside them, a simple side effect of their lust for each other. Lying down next to her sister, Lina kissed her. 

-You see, I had nothing bad in mind. Just a little bit of innocent sisterly bonding.  -You're right. We really ought to come back later. Let's head back to camp and clean up for now.

And so they went, no longer rivals and closer than ever.

Later that night, Rylai was staying up late, searching for a spell.

"Ah! This is it. This should make for some exciting change..."
She grabbed the Blink dagger and cast the spell, watching as her lower body transformed in a flash of light. When it was done, a large cock hung between her legs, bigger than her sister's.
"Well, it's time for them to meet their new Goddess..."

And she disappeared in a blink.

Rylai appeared in the middle of the desert in front of the perfect city. It was smaller than the previous one because she wanted to start with something a bit more intimate, but it was obviously opulent. It was fairly hot, even though the sun was setting. This would soon change. Approaching the city, Rylai cast a simple cantrip. She watched as clouds formed up above the city and snow quickly covered the metropolis, the air getting cooler. The cold air sent chills up her spine as it touched her naked body. The temperature had reached a level she much preferred, but the people down there didn't have the same opinion. They had never seen snow before and weren't prepared for the cold. They didn't have coats or heaters. The sudden storm created panic as everyone tried to find somewhere to stay while it passed. That's when Rylai stepped in, making the blizzard disappear as fast as it came. The masses moving below moved like tiny insects; they were inferior beings unable to adapt to the changing weather. Being a nice girl, she would help them.

"Aww, you guys look like you're freezing. Good thing I was around to save you. Since you don't have geothermal pools, I guess I'll just have to improvise."

She dug a hole by moving her feet in the center of the city, crushing the buildings carelessly as she slowly pushed the earth aside. Satisfied that it would be big enough, she stepped aside and grabbed her dick, aiming it at the hole below, letting herself go. A stream of piss came down, slowly filling her makeshift pool, some of it splashing around in the snow and some of it trickling into the earth, contaminating all the water of the city and replacing it with hot urine. When she was done she squatted down and waited. The smell was so strong no one really dared approach, so she lowered the temperature  even more. They no longer had a choice, staying out would mean they would freeze to death. She smiled as she watched thousands of people willingly jumping inside her urine. When the pool was finally full, she executed the next part of her plan : she blew on them, her icy breath having an effect on the liquid. It started moving, swallowing people and it stopped. She had created a thin layer of ice, barely visible to her, and trapped them under.

"Well, that should keep you safe for a while. The warmth won't leave too fast since it's in a tight container."

The people trapped under tried to swim up to breath, but  they couldn't since there was a thick layer of ice on the surface. She watched them fight against the small film of ice, punching and kicking it, but to them it was several inches thick. They were too weak to break it so they drowned one by one in her piss; the last thing they saw was the smiling face of the blonde giantess, uncaring of their fate. When there wasn't any more movement in the pool, she left, knowing she could simply leave them there in her bodily fluid would do the rest. Their bodies would be broken down by her urine, the acid dissolving them and erasing any trace of their existence. Satisfied, she moved on to go and help more people. 

Spotting a big crowd nearby, she moved above them and squatted above them."Maybe you've heard that smearing yourself with fat could help to isolate your body from the cold. Well, I don't have any fat, but I got something else you could use." Spreading her asscheeks, she aimed her butt at the crowd below and pushed. Her excrement fell on the crowd, crushing or trapping those under. She felt great and much lighter. Looking down, she couldn't believe these insects were actually doing it : they ran to her shit, desperately covering their bodies with it. The smell made them nauseous but at least it was warming them up. She decided to let them live, finding it pretty disgusting herself; she didn't want to get shit on herself, but the feeling of emptiness in her belly gave her an idea. Moving to another crowd, she sat in front of them, her legs blocking their way. Pulling her butt cheeks apart she relaxed her anus, spreading it open in front of them.

"You better get in quick if you don't want to freeze. You'll be warm and safe in there. I don't have all day, so you better move fast."

Not having much of a choice, the people took their chance. They fought each other to get in not wanting to be left to freeze. She barely felt them tickle her anus as they got inside her. When about half of them were in, she let her butt cheeks go, trapping them inside and letting the others outside. Moving her ass above them, she slowly lowered herself and ground them to paste under her ass. She thought about the people inside her. She had no intention of letting them out soon. She would eventually forget about them and they would die from her body's natural functions, she would eat and digest food, and they would get overwhelmed by the shit in her colon. Some of the weaker ones would probably be saved from that, they would choke and pass out long before.
She was getting really hard now and couldn't wait to try her new cock. Lying down, she created another blizzard, lowered the temperature everywhere around her and covered herself with snow. The only visible part of her body was her great dick, standing like a pillar in the eye of the storm. She was in the middle of the city, so she hoped some of them would make it in time. She simply closed her eyes, relaxed and waited. They would come; her cock was the only source of heat left in the city. It took a few minutes, but eventually she felt them hugging her dick. As more people came, they were forced to climb over each other and to go up the massive member to be close enough to its heat. They started crawling on her glans, stimulating her most sensitive part. Precum dripped down along her shaft as people tried to stay against her cock. Those on her tip tried to keep balance on the dangerously twitching penis. Those who fell either dropped down to their deaths on the sides or fell into her urethra, sinking down in her precum. She understood the pleasure of having a cock now, the feeling of power and control she had as they unwillingly served her, enslaved by her flesh, was amazing. Her manhood would decide of their fate, and it had made its decision : it would happily trade their lives for an orgasm. And so it did, an explosion of pleasure coursing through her body, her hips raising in to the air as bursts of cum came out of her balls. Falling back down, the cum covered her dick and the area around it. She froze it with the people stuck in it and removed the icy cum when her cock softened. Getting up, she looked around for survivors, sucking on the phallic popsicle. 

"Mmm, this is really good. I should take a day off and make a couple of these to share with the others. I bet there are a couple of cities that would really happy to help me with that."
Satisfied with her work here, she left to rest. She would come back soon, expecting her studies would be a lot more fun in this world...