Twilight and Spike made it through the jungle and somehow fell into a sewer.
"Spike, that's the last time I let you direct me through a jungle at night."
"Sorry."
Later on, Twilight and Spike ventured through sewers solving puzzles and fighting off Wendigo Mutants. Then, they made it into a big mausoleum. But the sister and the brother stopped their stinky sightseeing only to hear giant footsteps that were made by none other than... a giant mutated rat.
"I hate rats."
"Werewolf Form, remember?"
"Oh, yeah. Hrrk!" Twilight grunted as she lunges her body forward in pain and turns into her Werewolf Form again.
Twilight felt the pain, primal rage and primal hunger return once again as she grew in size, muscles, and fangs. Soon, the battle started to commence as the giant rat swung his right paw at them. Luckily, Werelight managed to quickly wrap her tail around Spike's waist as she made a huge evasive jump. And then she started to somersault forward in the air and come back down and deliver a powerful slash with her left paw; killing the creature instantly.
After that was done, Spike pulled the needle out from his bag. In truth, it was a really tiny needle, which doesn't hurt much. Twilight stood on her two legs and lifted her left paw under Spike's feet, leading Spike to fall onto her giant paw. With his right paw, he injects the transformation reversing liquid into Twilight's right shoulder to, well, reverse her transformation. As soon as Spike pulled the needle out, Twilight started to cringe which told Spike to jump onto her back and clench the fur between her wings tightly to hold on as she shrinks, with her claws and fingers shedding back into her body, her fur shedding and falling onto the ground underneath her, and fangs popping out while new flat teeth grew back. Finally, her horn straightens out as she turns back to her normal self as the brown color turned white, and finally back to her original color. She falls onto the pile of shed fur, panting. Spike remained on her back, until he saw a yellow light beaming from in between the giant rat's left fingers. (More specifically, its index and middle fingers.) Spike stepped off of Twilight's back and stood on her right side until he started walking to the giant mutant with the yellow light. When he reached its menacing paw, he used his left paw to push the index finger away and used his right paw to grab what was inside.
Twilight started to wake up with a moan. Spike heard, and ran over to his sister and started speaking as he ran. "Twilight, look! I found a Primal Stone between the rat's index and middle fingers!" He finished as he stopped in front of her with his paw in front of her face.
Twilight, however, sensed it had a smell, thanks to her nose that Spike unknowingly placed in front of. She covers her nose with her right hoof and took the pill with her magic and walked over to the sewer to clean it, despite its murky substance. Then, with a water bottle, thanks to Spike, she drank the water that carried the pill down inside her throat. Next, she started gasping for air like she was underwater. "Can't... breathe!" She said as she held her neck with her hooves and accidentally fell into the water. Spike ran over to the ledge with a gasp. Then he saw a yellow light glowing from within the water. Then his eyes widen as a face came out of the water.
"Spike, are you okay?" Twilight asked.
"Um, Twilight, I think you turned into a purple seapony that looks more fishy than pony-ish," he said as he points his left paw at her.
(Twilight's P.O.V.)
I raise my right eyebrow in confusion at what my brother just said and looked down at the water and look at my face. I gasped as I saw six gills, three on each side of my neck. I move my head to the right as I look at my reflection where four spines were poking out of my head with my head fins with the color of my mane with my purple stripe and pink stripe as they went down to the center of my back. My head looked more like that of the residents of Seaquestria. Instead of fins for hooves, I had what my Werewolf Form had, four fingers in the form of thin stems and pink fins in between them. I still have my equine bone structures for both my arms and legs. Except my legs weren't there, only a tail with dark blue fins just like my dorsal fins. Unlike my Seapony Form, I had pony teeth with four long fangs. Well, two that were long on the top that could stick out of my mouth, and two small ones that hide within my mouth. My wings looked exactly like the two times I was a Seapony. My eyes were still the same, but the white part of my eyes were colored yellow.
"Fishlight," Spike said. Twilight looks back at Spike in confusion and to what he just said.
"What?" She asks... with her head back due to the fact that she's still swimming in sewer water.
"Think about it, Twilight: you look more like a fish than a Seapony. But, I guess you can still call it a Seapony Form due to the fact that you're part fish. Not to mention your horns now a stem with a light bulb," he pointed out with his left finger.
Twilight looks up at her "horn," only to see that it was indeed now a dangling lightbulb. "Oh! I'm part angler fish. Which would explain why I have two long fangs protruding from my mouth," she says through her sentence with her right fin on her chin as she looks to the left. Then, the two heard rocks splashing into the water and realizing that the cave was about to collapse. Twilight grabbed her brother by the hips and pulled him into the water just as soon as a piece of the ceiling landed right where Spike was standing.
While underwater, Spike was having a hard time trying to breathe because he was pulled into the water without taking a deep breath. Twilight thought of something, and then she placed her brother in front of her face, and she placed her lips on his lips and started to inhale and exhale air into his mouth. But, only for a bubble to come between their lips until it encased his entire head just like the first time they visited Seaquestria due to the Storm King's invasion. Spike started to breathe frantically in Twilight's arms as she let go of the bubble that came from her mouth.
Spike sighed in relief. "Thanks. But how did you that would work?"
"I didn't count on blowing up a bubble, but at least you can breathe. I'm sorry for not warning you, but you would have been flattened like a pancake if I hadn't pulled you in."
"Thanks... and good point," he said with his left finger. Then he looked behind the left side of Twilight's face and saw a bright light, along with sinking rocks. "Look, Twilight! A way out!" He said as he pointed his right finger to a big hole.
"Good job, Spike! Now we can get out of here," she said as she twirled her body to the right for Spike to gently grab hold at the bottom of her neck. And, just like magic, she lit the brightly, dark waters with her lightbulb and started swimming fast as well as avoiding any falling rocks.
Outside the sewers...
Twilight and Spike emerged with Spike's bubble popping as soon as their heads came out of the water.
"Well, whaddya know, we're out of that stinking place," Spike started.
"And now we're in... a swamp," Twilight finished with disappointment. (Think of it like a bird's eye view.)
"Say, isn't this the place where Fluttershy delivered those frogs as well as us encountering that Hydra?" Spike asked.
Getting a good look around from right to left, she discovered that he was right. "You're right, Spike, we are at the Foggy Bog Swamp. Let's hurry before we run into that Hydra," she suggested.
"(Chuckling): Hehe heh, good idea,... "Fishlight," he snarked.
"You're really calling me that in this form, aren't you?" She asked.
"Yup. Just like Werelight, your Werewolf Form, too," he answered.
"Well, at least it's better than "Wolflight" or "Merlight," she replied.
"Do you want me call you by those names?" He asked.
"Do you wanna walk back to the Dragon Lands... by yourself?" Twilight replied.
"Nope! Werelight and Fishlight are better names," he replied back.
"Good. Now, let's continue on our journey to save Equestria," Fishlight said as she started swimming through the surface of the water.
"Okay, but, you won't really let me walk back by myself, now would you?" He asked as points his left finger to the sky and back at Twilight.
"Don't worry, Spike, I wouldn't really leave you behind, or let you walk back by yourself," she answered.
Spike gave a "phew," as he swept off a sweat gland from his forehead as they continued to skim through the water, without catching any unwanted attention.