Quilava never thought his first expedition as an evolved ‘mon would end so quickly...
Maybe it was the natural over-confidence of a newly evolved Pokemon, or just a lapse in concentration typical of an inexperienced explorer by himself, but the fire-type got ambushed right out in the open by a posse of Poliwrath, fainting him in a single attack. The young explorer laid on the ground exhausted and barely consious, holding out for a rescue before consiousness escaped him entirely. Right as he just couldn’t bear to keep his eyes open any longer, he saw two young Pokémon, a Zigzagoon and a Sentret, chattering and giggling to each other as if they were just walking home from school together... and were those diapers that they’re wearing?
●
Quilava woke up on a bed far softer and more comfortable than any other guild he’d been in. He laid cosy and warm under woolen blankets and on soft, cushy pillows, far nicer than the scratchy straw beds that he was used to.
“Wake up, sleepyhead! You’re all safe now!”
The Zigzagoon leapt right on to the Quilava’s bed and hopped right on to the fire Pokemon’s belly, his thick white diaper crinkling with every bound. Quilava groaned sleepily and shifted his position on the bed, only to feel a peculiar cushiness around his butt... 
“D-Did you diaper me!?” The Quilava fell out of the bed with the shout, leaving blankets and pillow strewn all over the floor, the Zigzagoon leaping out of the way just in time.
“Yes! It’s Guildmaster’s orders for every Pokemon in here to be padded up, to keep them nice and cozy and safe! The Zigzagoon explained in his high, breathless voice, sounding like a kid playing nurse.
“Argh, just get it off me and let me out of here!” The Quilava made for the door, flames spurting off his head as he pushed off... and then collapsed right onto the floor, his front legs giving way and leaving him slumped on the floor, his thick tape-up diaper breaking his fall with a loud crinkle. The Zigzagoon bounded over and inspected the Quilava’s fallen body, poking and prodding the bigger Pokemon’s stubby legs and brushing up against his diaper, the Quilava moaning slightly as the young Pokemon pushed the padding against his sensitive crotch.
“Don’t worry, you’ll be all better in a few days. Then you’ll be able to meet our Guildmaster! He’s so nice, and loves to wear diapers as well. I’m sure you will as well once you meet them, they’re so cosy and cushy~” The Zigzagoon says in his childish voice as the Quilava dragged his pained, thickly padded body back onto the bed. The Quilava gave no response, trying his hardest to ignore his present babyish circumstances and look at least slightly mature. “Bye-bye!” The Zigzagoon left, giving his padded rump a slight shake with his farewell, and left the Quilava alone lying askew on the bed, his diapered rump on full display.
A few more hours rest, and the Quilava regained enough strength to at least pick himself up and try to get that diaper off of himself. Are they expecting me to use it? He thought as he idly picked at the tapes. Treating me like a little baby Cyndaquil... did they just not see that I was evolved and thought that I was just some lost kid?
The sound of plates clattering interrupted the fire Pokémon’s thoughts as the Zigzagoon popped right back into the room, holding a tray in his mouth on top of which was a large spoon, a wooden bowl of what looked like mushed-up berries, some of which had already splashed off the top leaving purple drips on the outside of the bowl... and was that a bib beside it? 
“Hey... I’m feeling better now.. could you take this off and let me out of here?” The Quilava asked hesitantly. Really, he still was in no state to walk more than a few miles, let alone traverse a mystery dungeon, but the volcano Pokemon just wanted out of this bizarre guild. But the Zigzagoon ignored him completely, plonking the bowl down next to the Quilava’s head and grabbing the orange, flame-patterned bib.
“Time for your dinner, Quilly!” The Zigzagoon said, no enthusiasm lost from before. “I just need to put this bib on you and I can give you your di-”
Quilava knocked away the bowl, making an almighty crash as it cracked and split, leaving a trail of purple goo leading to a puddle of berry mush and broken pottery. “What are you doing?! Do you really think I’m just some little lost Cyndaquil? I’m an evolved Quilava, and I can take care of my own fucking dinner!” He leapt off the bed, flames bursting off his head as the enraged Pokemon lashed out at the little Zigzagoon – only for the little normal-type to deftly dodge out of the way and respond with his own tackle, toppling the larger Pokemon.
The Zigzagoon pounced on to the prone Quilava’s belly, his paws sinking into his cream chestfur. “What a naughty little Cyndaquil, refusing your dinner and saying a rude word~ The Guildmaster knows how to deal with naughty little Pokemon like you that don’t respect their caregivers... In the meantime, here’s something that should calm you right down.”
The Quilava moaned in response, still reeling from the attack and far too exhausted to resist any further. The Zigzagoon leapt off the dazed Quilava and went to a cabinet, returning with a bright red pacifier on elastic strap. 
“Open up~”
The Quilava could only whimper as his caregiver placed a paw into his mouth and pulled it open, gently inserting the pacifier and pulling the strap around his head holding it firmly in place. Once the pacifier was securely placed in the fire Pokemon’s mouth, the Zigzagoon pushed and prodded the Quilava onto to his feet. 
“I’m just gonna take you to the Guildmaster’s office. Don’t worry, after you’re with him all your rage will be gone...”
The babied Pokemon merely gurgled in response as his caregiver led him out of the room.
●
Quilava slumped along the corridors of the guild as he followed the diapered Zigzagoon, the humiliation of being defeated so easily twice in a row mixed with the pain and fatigue of his tired body causing the fire Pokemon to passively accept his babyish treatment. The grumpy Quilava couldn’t provide a starker contrast to the Zigzagoon, happily bouncing along as if he didn’t have a care in the world, his bushy tail wagging above his thick pampers as he made his way to the Guildmaster. Soon the two made their way to the main hall of the guild. It was a glorious sight, the vaulted hall bathed in the light of sunset beaming through a massive arched window, colouring the room and the various Pokemon inside in a golden glow. If the Quilava hadn’t just been beaten by a little kiddy Zigzagoon and stuck in a diaper, he may have even been impressed.
Two thickly diapered Pokemon, the Sentret from the rescue and a Poochyena, ran up to the two of them as they entered the room and nuzzled up against the Zigzagoon. “Hi Ziggy!~” the two of them greeted in unison, the pair’s high pitched voices making the Quilava cringe slightly. “How’s our new friend doing?” the Sentret said, pointing with her bushy tail towards the embarrassed volcano Pokemon.                
“He’s fine, but he’s been a naughty Cyndaquil, so I’m just gonna take him to meet the guildmaster.” The Zigzagoon turns to look right in the Quilava’s eyes. “Y’see? If you just behave, maybe the Guildmaster will let you become a rescuer just like us!” He merely suckled on his pacifier in response, his anger and embarrassment clear in his eyes. Meanwhile, the Poochyena sidled right up to the fire Pokemon’s butt and buried his muzzle in his padding, squishing it up against the Quilava’s rear. The Quilava squirmed, jerking away as the canine Pokemon sniffed his rear. He tried to shout at the Poochyena to back off, but the pacifier turned his angry words into a series of incoherent muffled sounds.
“Hey! Just try’na be friendly!” The Poochyena responded, prodding at the padding with his paw. “That’s just how we greet each other round here!”
“Yeah!” the Sentret added. “What’s the point of being such a fluffy and adorable ‘mon but not letting anyone nuzzle up against you? So selfish!” The three unevolved Pokemon leapt onto the Quilava, the tired fire Pokemon submitting under the weight of their cuddles and nuzzles. After a few moments of intense hugging and snuffling from the three Pokemon, they leapt out, leaving the Quilava even more dazed and his fur thoroughly ruffled.
“That was a nice nuzzling session, wasn’t it?” The Zigzagoon asked to the Quilava as they continued towards the Guildmaster’s room, the fire Pokemon responding only with an embarrassed suckle of his pacifier. “If you want more cuddles, I’m sure the Guildmaster would be happy to give them to you!” After a few more steps the pair were at the Guildmaster’s ornately-carved door, its height dwarfing the two Pokemon. The Zigzagoon reared up on its hind legs and knocked on the door, his diaper squishing on the floor. 
After a few moments the door opened, revealing the Guildmaster – a tall, powerfully built Noivern wearing just a thick white diaper with full confidence, looking very much the image of a powerful, battle trained leader despite his babyish attire. Quilava reared back, first from the incongruous sight of the fully evolved dragon in thick padding, but then from sudden recognition. The fire Pokemon tried to speak, but all that came out was muffled gurglings from the pacifier stuck in his mouth.
“Is this that insolent Quilava you rescued yesterday?” The Guildmaster asked the Zigzagoon.
“Yes!” The Zigzagoon turned to the Quilava, rearing up to look right in his eyes. “This is Noivern, our guildmaster! Don’t worry, he’s not as scary as he looks!”
“I’m sure the little Quilava won’t have anything to fear. The two of us just need a little time together to rectify his behaviour.” With that the Zigzagoon bounced away, leaving just the two of them in the room. 
"Looks like you have something to say...” The Noivern pulled the pacifier out of the babied Quilava’s mouth, leaving it hanging on the strap around his neck.
“N-Noivern? The leader of the Steelwing guild? What are you doing wearing... that?!”
The Noivern chuckled in response and made his way to the two smaller Pokemon, crinkling with each step. “I could say the same of you... you look like you’ve not quite used to wearing our uniform.”
“...Uniform?”
“It’s a guild rule – all guild members have to wear a thick, robust diaper when out exploring dungeons. Of course, we can just wear them whenever we want – and put them on the folks we rescue too. It’s the guildmaster’s responsibility to make sure every one of their charges is as safe and comfortable as they can be, of course~” 
Noivern reached down to pick the Quilava up, the strong dragon effortlessly lifting him and pressing his head against the dragon’s fluffy neckfur, resting a paw on the bottom of his pamps. Quilava pouted, but didn’t even bother resisting – after all the embarrasment of before, he now just wanted a rest, diapers be damned. The Quilava found himself being carried across the room, the Noivern bouncing him with each step, and placed down on a bed of soft grass, next to which was a glass bottle filled with milk, along with a bowl of mashed-up berries much like the one he had hurled across the room earlier.
“I head you quite rudely refused your meal earlier today.” Noivern said, gently stroking the Quilava’s cheek. “I can’t have any of my charges going hungry, so I’ll feed you myself. You’ll have to promise to me not to toss your food away, though.” The Noivern looked Quilava right in the eye. “Do you promise to be a good little Pokemon and not throw a tantrum?”
“Y-yes...” The Quilava mumbled, as the dragon Pokemon leaned over his prone body, a warm, sincere smile on his face. He didn’t want to repeat the humiliation from earlier, especially with a fully-evolved dragon present, but the guildmaster’s gentle voice, the warm bed he laid on, even the soft squishy feeling of his diaper – it relaxed him, getting rid of any defiance to the babying he was receiving. The Quilava even managed a soft smile in response to the Noivern’s, fully accepting the bigger Pokemon’s care.
“Okay!” The Noivern grabbed the bowl of berries and spooned up some berries. “Open up~” The Quilava complied, opening up his mouth without complaint as the dragon fed him, one spoonful at a time. Once the bowl of berries had been emptied, Noivern handed the Quilava the bottle of milk. 
“Have as much milk as you want, little Quilava. You must be thirsty after wearing that pacifier.” Quilava blushed, but dutifully drank the milk down, nearly emptying the bottle in one drink. “You really are thirsty!” Noivern said as he stood up and wandered across the room, waddling slightly from the bulk of the diaper as he picked up two more bottles of milk to give to the babied Pokemon.
Quilava was midway through his second bottle of milk when a sudden pressure came across the fire Pokemon’s bladder, him realising that he hadn’t relieved himself since he was first put in diapers at the guild. Of course, Quilava knew what the diapers were meant to be used for... but he couldn’t bring himself to wet himself right there, with Noivern looking right at him. He blushed at the mere thought of it, dropping the bottle of milk and shielding his face with his paws.
“Something wrong, little Quilava?” Noivern asked.
“Uh... I-I need to...”
“Use your diaper? Of course you can, that’s what its there for! I’ll have a change ready for you, I just need to grab a fresh diaper.” The pressure in his bladder had grown to an almost unbearable point – the fire Pokemon knew that he was going to have to release the full contents of his bladder, and he was going to have to be do so right into his diaper like a baby Pokemon. A tear came to the Quilava’s eye as he tried to control his full bladder.
Quilava rolled over slightly towards Noivern – he held a fresh diaper, much like the one the fire Pokemon was wearing but neatly folded up, and a canister of baby powder.
“I’m all ready for your change. Just let it all go, don’t worry about it leaking.” Noivern pushed down gently on the Quilava’s cream-furred belly, putting pressure on his bladder. The Quilava winced as a few drops of pee leaked out, leaving a little moist patch inside his padding. Noivern pushed a little harder, and the fire Pokemon twitched – and completely lost control of his bladder, pee saturating the inside of his diaper and leaking out, leaving trickles of the Quilava’s pee dripping over his fur. The Quilava froze for a moment, completely in shock, then started sobbing. Noivern picked up the crying Pokemon and gave him a warm hug, wiping away the Pokemon’s tears.
“Don’t worry, I’ll get you cleaned up and changed right away. You’ve been such a sweet little Quilava, I never would’ve guessed that you were the same Pokemon as the one that was so horribly rude to Zigzagoon”
The Quilava blushed, but smiled hearing Noivern’s words as the dragon laid him back down on the bed. He never would’ve thought that he could feel so warm and loved from being put in a diaper, much less actually using it, but there he was happily receiving a diaper change. Noivern opened up the soaked diaper, wiping the smaller Pokemon clean, and slides the fresh one underneath him. After a liberal application of baby powder, Noivern tapes him back up, leaving the Quilava securely padded up in a fresh, poofy diaper. The dragon Pokemon picks Quilava up, bouncing him gently in his arms as he carries him out of the room and into the cavernous main hall of the guild, now lit only by the light of the moon.
“Looks like it’s time for baby Pokemon to head off to bed. Get a good rest, you can stay here until you’re feeling alright again.”
Quilava merely smiled in response as the dragon gently laid him down on the bed he had woken up on at the start of the day and draped the blankets over his resting, thickly pampered body.
“Good night, little Quilava.”