After taking care of business in the Coliseum, allowing them to grow as a team and as a group, everyone returned to the ship as Sora warped them back to Agrabah before blasting off in the direction they had started in before Monstro surprised them and swallowed everyone for a time. Radiant and Fluttershy spent their time in the other dimension, the former working with all of the kobolds that were now living there as she started to turn all of the materials she had been given into items they might be able to use, as she had talked with a Moogle back in Traverse Town during their time there. Fluttershy continued to work in the garden she was growing, where Sombra confirmed that somehow growing things and harvesting them gave her more experience and helped her become more like the others, 'leveling up', as she called it, to match the pace that the rest of the team had set. In addition to that Sombra found that Squeak worked as Fluttershy had told them, he looted chests and gave the pair everything he found during their visits to the various worlds, allowing the pair to sort out the treasure so they could be more ready for whatever the future held for them.
Sombra, on the other hand, simply resumed her training with Riku and her own magical training, the latter involving her getting more comfortable with the new types of magic she had discovered so far, tapping into how to wield the power of time and gravity until they were second nature to her. Of course it wouldn't be that simple, she knew that much without being told, but it was a worthwhile goal to have for herself, mastering the lowest tier of spells they had discovered so she could cast them without a second thought, literally just think about it and loose the spell in question. That seemed to be possible for the likes of Fire and Blizzard, the elemental spells, but mastering time and gravity magic was definitely harder than she was expecting, which was good for her since she felt that having things too easy would just be boring. She also made sure to change up the abilities of the training dummies, effectively making them so they could move like their foes so she and the others could have a challenge, which Riku, at the very least, seemed to appreciate.
During some of their breaks Sora also joined in on the training, either clashing with Riku like old times or just standing by his friend's side as both of them rushed Sombra, something that made her happy since it meant both were using their training from the Coliseum to the fullest, meaning they'd be ready for the next world.
While Sombra dealt with her body's new feminine changes, which Radiant had told her about so she could be prepared for the future, she did notice that Riku like to glance her way every now and then while they were traveling through space, like he was actually crushing on her and had no idea how to say anything about it to her. One thing he asked her was how to use the Darkness without being overtaken by it, as he noticed shadowy bits following Sombra and assumed that she had some sort of power that the others didn't know about, causing her to sigh as she agreed to give him some pointers. While she had an unfair advantage over everyone else, due to her birth nature as an umbrum, she had learned how to channel and use her powers as if she were a normal pony, mastering them to the point where she had nothing to fear from the Darkness, and a few of the minor lessons could be passed onto Riku with ease. There were other things she could tell him, about how to use the Darkness without it corrupting you, but decided that, for the time being, they would focus on building his resistances so when she reached the true lessons he'd be able to keep up with her training.
Other than that there wasn't much else to do, where Sombra decided to practice a few of the new dishes she had found in the cook books they had been given, some of which she could actually make with the ingredients on hand, and, much to her surprise, the others seemed to like everything she made. She knew that her skills weren't the best in comparison to those of their home world, those chosen to be grand chefs and whatnot, but it was still a surprise to see them like what she made, even dishes she was experimenting with to see what worked and what didn't. Of course she found that using a number of items from the garden made things taste slightly different from what she was expecting, in fact they tasted far better than she was expecting, and found that it only made Fluttershy tell her that she'd make sure she had everything she might need in the future. That, of course, meant that anything and everything that could be planted would be added to her various farms, to be grown and then harvested to be placed on the table at some point, where Sombra decided not to get in her way, as it was actually nice to prepare dishes like this.
Eventually, after another few days, they reached their destination, a new world that seemed to be entirely underwater, a fact they confirmed because it looked like there was an underwater kingdom and the area around it seemed to be in some sort of cave system, or maybe that was just the style of the world from space's perspective.
"Okay, problem... how do we land in the sea?" Sora asked, coming to a stop in the normal space he usually stopped in as they approached a new world, because unlike all of the other worlds they had visited this one seemed like it would be far too dangerous for them, especially since none of them could breathe underwater.
"Simple, you teleport us down like normal." Donald replied, causing everyone to glance at him like he had gone mad, since that seemed like a horrible idea since they had no idea where the safe area was resting, meaning they might get seriously hurt if they did what he was suggesting, before the duck pointed at one of the controls, "The Gummi Ship comes equipped with a device that provides a magical shield that allows us to integrate with the residents of a world... if we don't change, then that means we're just fine with our current forms."
"Why are we learning about this now!?" Sombra remarked, as this seemed incredibly important to know about, especially since it seemed like a way to hide themselves when they visited the various worlds, and yet here the duck was, keeping information from them, making her wonder if she would take away his dessert again.
"It wasn't important before, now it is. Simple as that." Donald stated, as if that solved everything, when it most certainly did not in the eyes of everyone else, causing Sombra to look at the Scanner for a moment and found that it had a hand like a clock, currently pointing at 'Transform' that had a glowing light above it, "The pointer will tell us if a world needs us to disguise ourselves, so we can be prepared for whatever our new forms are and not be freaked out."
Everyone glanced at each other for a moment before telling Sora to do it, where he nodded his head, activated the mode that would keep the ship hidden, and then warped them down to the world's surface, or what counted as it's surface this time around, all while everyone braced themselves accordingly. Sure enough they warped down into the sea, deeper than what all of them were expecting, though everyone ended up missing the majority of their clothing for some odd reason, a reason that became known to Sombra as she found that they could breathe underwater just fine. She then found that all of them had changed, as Sora's lower body had been replaced by that of a blue dolphin, complete with the dorsal fin, while Donald's lower body was that of an octopus and Goofy was a turtle with his head, though while Sora seemed happy with this it was clear that the duck wasn't pleased. Sombra found that she, Radiant, Fluttershy, and Riku were sort of the same to Sora, their lower bodies had been replaced by fish tails, though while Riku's was dark it was easy for Sombra to see that hers, Radiant's, and Fluttershy's tails were the same color as their actual tails, plus their bodies were different, as their chests and faces were tanned, like Sora's.
The downside was that none of them really knew how to use their new bodies, even though they could guess how to move by just swimming around the area that was around them, an area carved out by the currents of the sea no doubt, and as they moved around Sombra found that she and the other Equestrians were missing their horns and wings, no doubt to help them blend in better.
"You know, this isn't too bad." Sora commented, though as he did his best to swim around, while Donald sunk and Goofy moved through the water, Sombra noticed one last thing, she and the other girls had what appeared to be seashells for bras, her and Fluttershy having larger shells than Radiant.
In that moment they found a red haired girl, with a green lower body, swimming towards them with a yellow fish and a small red crab following her, the crab calling the girl 'Ariel', though the newcomers stopped when they saw the group and Ariel seemed far too curious for her own good. She seemed far too trusting as well, that much Sombra could tell, and while both Flounder, the yellow fish, and Sebastian, the crab, seemed unwilling to place their trust in some newcomers they had only just encountered, which Sombra agreed with. As she gracefully swam around them, however, Sombra and the others knew that they must have been swimming away from potential enemies, as one could feel the Heartless that were coming and the others knew to trust her feelings, but Ariel's studies caused them to focus on her. Fluttershy told her that they were from another sea, one that was different from the one they were now in, though in response to that Ariel asked them to tell her all about their old home, and, upon seeing how bad some of them were swimming, even offered to teach everyone how to swim in exchange for that information.
Sebastian wasn't too pleased with this idea, and stated that 'King Triton' wouldn't be happy either, but Ariel did it anyway and the two sea creatures beside her helped her out, meaning she had to be a princess in the underwater kingdom that was part of this world. They taught the group how to rise and dive, moving with the currents, and Ariel even showed off how a mermaid should move, since she thought the boys were merman and the girls were mermaids, causing them to do as she did to make sure they understood how to move. Sombra, Fluttershy, and Radiant had to admit that this was nice, which might be due to the fact that the World had granted them their previous forms and might have left some traces for them to get used to their other new forms, like their new mermaid forms, faster than others should, but they weren't about to complain about this. To prove that they were able to swim normally everyone had to chase Flounder and catch him, and when one was done they swam off to the side, where Ariel was waiting, and watched as the others did the same thing in no time, proving that Sora and Riku were also fast learners as well.
That was followed by a number of yellow jellyfish Heartless coming at them, causing Ariel's group to swim away before the Sea Neons reached them, though as the others readied their weapons Sombra decided to do something different, due to the fact that using a scythe in this world seemed like a hard thing to do. Her plan was to use magic, plain and simple, so when one of the new Heartless came at her she swam off to the side and loosed a fireball right into the side of it, finding that her spell wasn't extinguished by the water that was around them, slamming into the creature and weakening it so one of the others could take it out. Riku was the one that came to her aid in fully taking down her targets, noticing which foe she was interested in and rushing at them at the same time that the spell left her hand, allowing them to tear through the Heartless as her darkness seized the freed hearts. Radiant was in the same boat as Sombra, her bow didn't seem to be the best option right now, so she focused on using her Keyblade, just like Fluttershy did, all while Goofy spun around with his shield on his back as Donald fired spells at will, allowing them to eliminate the group of Heartless.
When the coast was clear, and they were sure of that, Sora called out for Ariel's group to join them, as it was safe, causing the trio to come out from the side area that they had hidden themselves in and swam up to the group as everyone put their weapons away for the time being.
"Wow, that was... SO AMAZING!" Ariel commented, showing them that she must have been watching them, hence why she was able to join them so quickly after Sora called for her to come out, while at the same time it looked like her fish friends were either indifferent towards this discovery or were holding back their excitement, before she regained herself after seeing the look Sebastian was giving her, "Sorry. We were chased here by those monsters... wait, what if they decide to head to the palace? We had better head back and check on daddy."
"Considering what the Heartless can do to people, we should check on your father." Riku said, because he realized that if the King of the Seas knew that they had saved the day, by saving his daughter and repelling the Heartless, they might be able to deal with this world's Keyhole in no time and continue to the next world without delay, not that he hated this world since it was rather nice.
Sebastian seemed nervous about the idea, bringing strangers to the King of the Seas, though he couldn't fault their power and decided to trust them, which was why he and Ariel started to retrace the path they used to flee from the Heartless, all while making sure Sora and the others knew that they would be defending them in case the creatures returned. Sombra noted that there were golden trident markings on a number of walls and asked about them, where Ariel informed them that they were supposed to lead the residents of the kingdom to her father's palace, so if they ended up getting separated everyone would know where to meet up. It was an interesting thing to discover, though for the time being they focused on swimming through the water, enjoying themselves as Riku told Ariel that they weren't used to waters like this, which she and her companions seemed to believe as they continued to swim through the sea. In addition to that they found a fair number of Sea Neons that popped into existence, causing Ariel to pull back as the group dealt with them over and over again, where Sombra had to assume they'd give her some sort of water based ability, given the world they're in.
While they swam, however, Sombra felt a familiar tug, which seemed to be identical to the fragmented heart pieces she had discovered so far, informing her that another one had to be somewhere in this world, causing her to wonder which emotion or feeling it might be this time around.
When Ariel brought them to the palace, which was an imposing structure that seemed right at place under the water with it's underwater designed pillars and spiral dome, the group swam there for a moment, taking in the sights while seeing a path leading right to the entrance. In addition to that Sora pointed out another new Heartless, a Soldier that wore what appeared to be sea based armor, making this type a 'Sea Soldier', especially since they carried tridents, though that didn't stop the group from parrying their attacks and taking them out. The oddest thing was that there were a number of Ghosts in the area as well, though Sombra guessed that it made sense due to the fact that they couldn't breathe like the rest of the Heartless, or at least she assumed so since this was a first for them. Either way the group dealt with the Heartless that were getting ready to attack the palace and cleared the rest of the area, before glancing around for a time to make sure that no more were coming this way, causing Ariel to head towards the palace with everyone following after her.
She brought them right to the throne of the palace, which seemed to be a conch shell modified into a throne and raised so the King could look out over all that were around him, while the King seemed to be a buff and imposing merman with a long white beard and carried a golden trident that allowed him to annihilate a group of Sea Soldiers in an instant.
"That was too close. As long as I have my trident, the greatest weapon in the sea, I will not tolerate those creatures inside my palace!" the merman, King Triton, stated as he lowered his trident, where he floated there for a moment as he made sure there were no more Heartless coming at his domain, though once he felt everything was secure he sat back down and relaxed a tiny bit, and just a tiny bit since he was still serious, while keeping his trident at the ready, before he looked at them for a moment and frowned, "Oh, Ariel... when will you learn that it's dangerous out there? There are strange creatures out there, and I fear for your safety now more than ever before. Now, who are your companions?"
"I am called Sombra, your Majesty, and these are my friends Riku, Sora, Fluttershy, Radiant Hope, Goofy, and Donald," Sombra replied, bowing her head slightly as she found that the others did the same, no doubt allowing her to take the lead this time around, as while two of them knew of her former position the others didn't know her past, something she would like to keep that way, before raising her head again, "We're actually here to fight the Heartless, those 'strange creatures' you mentioned, by tracking down their source and taking them out before they do whatever it is that they're trying to do... and, from what we can tell, their plans are to hurt people, take their hearts, and find a special secret area within the seas."
One thing Sombra had convinced the others to do was not mention the Keyhole by name, just in case the people they spoke with got annoyed with them or used them to seek it out, and while she danced around the topic, in a sense, she could see that King Triton seemed to have an idea of what she was talking about.
"I see. Well then, you have my thanks for keeping my daughter safe from those 'Heartless'. Sebastian, why don't you show them around a little, while I secure the palace?" King Triton said, where it was clear that while he might have an idea of what the group was looking for, he also didn't want to mention it in front of Ariel, so he couldn't get mad at them since Sombra had keep the information to herself, "Ariel, we'll talk once I'm sure we're safe."
As Ariel nodded the group bowed their heads once more and followed her into the rest of the palace, knowing that it was only a matter of time until they encountered the villain of this world, tore their schemes apart, and found the Keyhole, so for the time being they decided to relax a little and followed the lobster as they wondered what else this world might throw at them next.