Route 5: Golden Aether

Date Written: 

Death, pillaging, and destruction- this has been the fate of Fódlan for the past five years. War has claimed countless lives, and many believed Byleth’s to be one of them. She disappeared shortly before Garreg Mach Monastery fell, and her students in the Golden Deer house assumed the worst when they couldn’t find their beloved professor. They were overcome with joy, if not a little confused, when she reappeared after years of presumed death. Byleth’s keen strategy and battlefield prowess allowed her former students to retake Garreg Mach and begin the fight to save Fódlan. Although her students are now older, they still have many of the same quirks from their days at the Officers Academy.


“I can’t believe it! She wants me to go out on another mission? I just got back from the last one!” Hilda yelled as she entered the barracks.

“Um… I’m sure she wouldn’t send you unless she thought you could handle it.” Said Marianne.

“Of course I can handle it!” Responded Hilda. “But so could anyone else! Did the professor forget that I hate fighting? I’m much better for morale back here at the monastery.”

Lysithea snapped her book shut, causing both women to jump.

“Will you shut up? I’m trying to read over here.” Said Lysithea. “If you want to be useless that’s fine, but I’m trying to research some strategies to use in the next battle.”

“Doing the professor’s busy work again, huh?” Sneered Hilda.

“It’s not busy work!”

“Oh really? Then why is it that you’re always doing research for the professor while she has tea with the boys? I bet she doesn’t even read your reports.”


“I think the problem is obvious.” Said Leonie, who had been drinking for the past few hours judging by the empty tankards on her table. “The professor needs to realize that we’ve become a lot stronger in these past five years. We aren’t the fresh faces she knew when we were just starting at the academy. If Jeralt compared me to her there’s no question that he’d recognize me as his best student.”

“Uh… Ok? And how would you fix that?” Asked Hilda.

“I don’t think there’s anything that could bring Jeralt back…”

“No, I mean the problem with the professor. How would you show her that she can’t treat us this way?”

“Oh, that. We’ll need to ‘borrow’ a few things, but she’ll never underestimate us again.”

“M- Maybe we can just… talk to the professor?” Said Marianne.

“Relax Marianne,” said Leonie. “Follow my plan and it’ll all be fine.”

Hilda and Lysithea nodded in agreement as Leonie gave them all a mischievous smile.


The halls of Garreg Mach danced with shadows as torches flickered in the night. Byleth always enjoyed her late-night walks; it gave her time to think and plan for the next day. Almost nobody else was awake at this hour, so she rarely had to deal with interruptions. This night, however, would be very different. Byleth never noticed the person who jumped out from behind a pile of crates until she was already in a full nelson hold.


“If you had actually listened to Jeralt when he was alive, you would never have fallen for such an easy ambush.”

“Oh, Leonie.” Sighed Byleth in relief. “Yes, I know. Jeralt also knew that you should never attack your superior officer. Now let me go before I decide to report this incident.”

“I don’t think that’s going to happen.” Said Hilda as she sauntered out from the shadows. She playfully spun the length of hose she had ‘borrowed’ from the infirmary at her side as she walked towards Byleth.

“Hilda? Don’t tell me you’re a part of this too.”

“We think it’s time you realize that you can’t boss us around like we’re still your students.” Responded Hilda. She held the end of the hose up to Byleth’s face and leaned in. “Now open up.”

Byleth wriggled and shook her head as Hilda tried to shove the hose in her mouth. Hilda tried to hold Byleth’s head with her free hand to make it easier, but had no luck with keeping the hose in Byleth’s mouth.

“Will you hurry it up?” Grunted Leonie as she struggled to keep her hold on Byleth.

“I’m trying!” Said Hilda. “But she keeps spitting the hose out!”

Hilda glanced down and noticed that Byleth’s armor exposes her midriff. A smirk flashed across Hilda’s face as she pulled the hose back and jammed it into Byleth’s belly button.

“There! I did it!” Cheered Hilda as she took a few steps back, still facing Byleth. Hilda smiled as she took in a deep breath, causing her already ample chest to strain against the fabric of her dress. The strings on her corset strained as Hilda continued to inhale, emitting a soft creaking sound as they struggled to contain her expanding body. Once Hilda had inhaled as much air as she possibly could, she placed her end of the hose into her mouth and blew.

Byleth let out a startled gasp and blushed as the air entered her body. The first exhale just made Byleth feel a bit tighter, but no physical change was obvious. Hilda removed the hose from her mouth as she took an even deeper breath, her dress nearly splitting in half to accommodate her growing bust. Once she felt like she was about to burst, Hilda put the hose back in her mouth and blew again. Byleth’s trim stomach slowly puffed out like rising dough as the stream of air entered her body.

Hilda repeated this process over and over. Byleth’s armor restricted her expanding body, which caused the air to migrate into areas of less resistance. Her thigh gap quickly closed as her legs thickened, and her ass rounded out a little more with each breath that Hilda blew into her. The belt that held Byleth’s dagger began digging into her hips and stomach as she continued to inflate, finally snapping off like a rubber band as it could no longer contain her expanding body. Her stockings soon followed suit, ripping along the seams as pale bubbles of skin forced their way through the threads.

Byleth’s upper body was also growing with every puff of air, causing her breasts to spill over the top of her armor. Each breath forced more air into her expanding bust, which had nearly tripled from its original size. Breasts the size of basketballs pushed against Byleth’s face as they began to obstruct her view. Her arms also grew thicker and became difficult to move. As each breath rebounded through Byleth’s body, her arms would become straighter and more rigid. Eventually, she was unable to bend them at all.

Byleth’s armor groaned from the pressure of her body pushing against it, but it was still holding strong. She resembled an exaggerated hourglass as Hilda continued to blow into the hose.  The hollow sound of air entering a balloon was all that could be heard between Hilda inhaling and Byleth whimpering from the mounting pressure. Hilda paused and placed her thumb over the hose’s opening.

“Hah…Hah… Ok, That’s all for me.” Hilda panted. “Come on Marianne, it’s your turn.”

Marianne trudged out from her hiding place behind the crates. She looked over Byleth’s swollen form but couldn’t bring herself to make eye contact with their victim.

“Mmph…M-Marianne? You agreed to thish too?!” Said Byleth, struggling to speak because her chest smothered most of her face.

“Well, we… professor, it’s just…” Marianne fumbled over the words as she tried to respond.

Hilda grabbed Marianne’s hand and forced the hose into it. A short hiss came from the hose as Hilda removed her thumb and replaced it with Marianne’s.

“Shut up and blow into the hose a few times, sheesh.” Demanded Hilda.

Marianne looked down at the hose, then up at Hilda. She shook her head “no” and tried to hand the hose back.

“Oh come on, it’s easy.” Said Hilda as she rolled her eyes. “just take a deep breath and blow. Here, like this.”

Hilda started to take another deep breath. Her corset had loosened from the dozens of times she had already done this, which allowed her to take in more air than ever before. The top string of her corset looked like it could snap at any moment as her breasts doubled in size and a tight little pot belly formed below them. Marianne feared that Hilda would make herself burst if she continued to inhale at this rate. Hilda looked at Marianne, who looked away and tried to hand the hose over once again. Hilda smiled as she cupped Marianne’s face in her hands- then locked lips with her and blew.

Marianne gave a startled squeak as her eyes opened wide from shock. Any other noise was pushed down by the torrent of air that Hilda was blowing into her. Marianne’s belly bulged out under her dress, making her look like she was a few months pregnant. Hilda inhaled through her nostrils and blew again. Marianne’s belly grew even larger, now making her look like she was full term pregnant. Hilda inhaled once more through her nostrils as Marianne tried to protest, knowing she was about to get another blast of air. Marianne’s stomach grew to the size of an exercise ball as Hilda blew into her, making the golden tassels on her dress to snap off and fall to the floor. Some of the air settled in her breasts as well, causing the loose material over her chest to snap taut as she expanded. Hilda broke the kiss and used her fingers to pinch Marianne’s lips shut.

“There, I did all the hard work for you.” Said Hilda. “Now blow that air into the professor unless you want a little more help.”

Marianne slowly lifted the hose to her mouth but paused when it was just inches away. She looked up at a very annoyed Hilda who began to take another deep breath. Marianne accepted her situation and nodded, causing Hilda to let go of her lips so she could put the hose in her mouth to blow. Marianne deflated back to her slim form almost instantly; the only evidence of her inflation being the tassels on the floor and a stretched-out dress. Byleth was not as lucky.

The large volume of air being pumped into Byleth caused her internal pressure to spike. Her body groaned and her cheeks puffed up with air, making her unable to speak. She squeezed her eyes shut as her face reddened, feeling like she could burst at any moment. A sharp popping sound was followed by the sound of her armor clattering to the ground. Byleth opened her eyes to see her body had not burst, but her armor had.

Her belly, no longer restricted by the armor, bulged outward immediately. Her stomach surged to 10 feet in diameter, causing her breasts to bounce as they settled in place. The buttons of her collar shot off into the darkness and her pendant fell to the ground. The sudden growth threw Leonie to the ground and knocked her unconscious, but her hold was no longer necessary to keep Byleth in this defenseless state. Her arms and legs inflated into rigid conical shapes, which caused the armor on her arms and legs to snap off and clatter to the floor as well. Her top was struggling to hold together as it barely covered her erect nipples, and her shorts were more like a thong. Creaking echoed through the hallway as her body struggled to adjust to its new size.

“That wasn’t so hard now, was it?” Said Hilda.

“You could’ve popped me!” Yelled Marianne.

“Don’t be so dramatic, I wasn’t going to pop you. We do stretches together every morning, I know you’re flexible enough to handle a little air.”

“That’s not the point! What if-“

Marianne was cut off as Lysithea stormed out from her spot behind the crates.

“Look at the professor! We were all supposed to have a turn at blowing her up, but you two nearly maxed her out.”

Lysithea grabbed the hose out of Marianne’s hand.

“Whatever, even if it’s only a few breaths I’m still going to take my turn.”

Hilda and Marianne continued to argue as Lysithea inhaled. Her small chest and belly expanded as the air flowed into her body, which caused her dress to start riding up and tighten a bit. She couldn’t hold as much air as Hilda, but she was still confident in her ability. Lysithea put the hose to her mouth and began to blow- or at least she tried. She strained to blow into Byleth until she was red in the face, but the immense pressure inside of Byleth’s body was too much. Air surged into Lysithea as she tried to fight against the blowback. Her lithe body started to expand at an alarming rate, putting massive strain on her dress as the stitches along the side began to pop.

Leonie slowly got up from the ground as the fog in her head dissipated. She looked up to see that Byleth was slowly deflating, and to her horror Lysithea was inflating on the other end of the hose. Hilda and Marianne had their backs to everyone as they continued to argue.

“Hey, you two! Shut up and help Lysithea!”

Hilda and Marianne turned around and gasped when they saw what was happening. Lysithea’s dress only covered the upper half of her belly as it continued to expand. Her stockings were also ripping as the air began to move to her ass and legs. Lysithea’s face showed sheer panic as her arms had also inflated into the “T” pose, making her unable to reach the hose. Hilda and Marianne ran to opposite sides of Lysithea and locked arms as they squeezed, forcing the air out. Slowly but surely, the air was pushed out of Lysithea and back into Byleth.  Once Lysithea was back to her normal size, Hilda took the hose out of her mouth and held her thumb over the opening.

“T-thanks… that was…” Lysithea trailed off.

“Too close.” Finished Hilda. “That could’ve gone really badly. I think it’s time we deflate the professor.”

“Oh hell no!” Yelled Leonie. “Not until I’ve had my turn!”

“You saw what happened to Lysithea, she almost popped! Unless you also want to pop I think we should end this. The professor clearly got the message.”

Byleth whimpered in agreement.

“I figured this might happen, so I came prepared.” Said Leonie as she ran back to the crates to pull out a bellows pump. “I can plug this into the hose to avoid what happened to Lysithea.”

“So that’s why you ran off to the forge,” said Hilda. “Fine, here’s the hose. Don’t blame me if something goes wrong.”

Leonie smiled like a giddy child as she inserted the bellows pump into the hose. She lifted the paddle and slowly pushed it down, forcing a gust of air into Byleth.

“How pathetic! You had your whole life to learn from Jeralt and this happens to you?”

Leonie pumped another gust of air into Byleth, causing her top to snap off and expose her breasts in their entirety.

“You should be ashamed, really. To waste all that valuable time with Jeralt.”

Leonie pumped a couple more times, causing Byleth’s shorts to pop off. Byleth was completely naked at this point, but that was the least of her concerns.

“You didn’t deserve to be his daughter! I did!”

Leonie kept pumping, causing Byleth’s body to pulse with each gust of air. Low creaks and rumbles emanated from Byleth’s overtaxed body.

“Leonie, knock it off!” Said Hilda. “She’s way too full!”

Leonie didn’t even acknowledge Hilda as she brought the paddle of the pump down again.

“How could you have that time with him and not care? It’s disgusting!”

Byleth’s was only getting tighter at this point. She was simply out of room, and each pump reminded her of that fact by causing a prickling sensation to wash over her whole body. All she could do was focus on staying in one piece and hope that one of the others would stop Leonie before she burst. Her skin turned translucent as the onslaught of pumps refused to end.

“And you never appreciated his swordsmanship! Or his sense of humor! Or-“

Leonie was cut off as Byleth popped like an overinflated party balloon. The blast of air extinguished all of the torches, leaving nothing but the moonlight to illuminate the hallway. Pale scraps of rubber fluttered down as the only things that remained of Byleth besides torn clothes and warped armor.

“Goddess help us.” Said Marianne as she sunk to the floor.

Author's Note: 

This is what happens when you have an inflation fetish and also enjoy playing the chess game that makes you horny. Over 100 hours in and I still don't know why female Byleth has such a ridiculous outfit. I also made sure to go with post time skip women so there's no issue with age. 

Average: 3 (3 votes)
Pennsylvania Ki...
Pennsylvania Kite Weather's picture
I think it's solid!

I think it's solid! First of all it's nice to see you experimenting with FE fanfiction again. This all may be a bit vague to readers with no familiarity of Three Houses, but I can say the personalities were pretty true-to-canon, especially Leonie's motivations which brought in the final act. I guess my only suggestion would be a bit of background regarding appearance or demeanor for the main players in the action. Here there's a couple different methods and detours sharing the air which gives something for everybody, though. Detail-wise, no complaints here! - it's all rather clear.