So, I tried a little bit of a different approach with this boss, letting you see its point of view as well. I may do this with the rest of the bosses as well. Enjoy!
"Well, this is the only place left." Sheik said as they approached the door.
"So it was the last place we thought to look." Ruto replied.
"Morpha's most likely inside. Are we all ready?"
Saria nodded "I think I'm ready."
"You look worried." Alta pointed out.
"I'm still concerned about Dark Saria…" Saria explained. She and Malon had already told them about what happened by this point "What if she comes back while we're fighting Morpha?"
"You said she stopped because she got bored with you, right?" Sheik asked, to which Saria nodded "Then we should have nothing to worry about. She's probably watching you right now, sure, but if she wants a good challenge, she'd wait until you become as such."
"You're sure about this?"
"Reasonably so."
"Either way, we should focus on Morpha right now." Ruto said "We'll deal with her if she comes."
"Right." Sheik agreed, nodding. They headed into the room, which had a pool of deep water in the center, with four platforms in it. The floor around the pool was, in turn, lined with spikes on the walls. The angle from the door kept them from immediately seeing if anything was in the water.
"...Where is it?" Malon asked, looking around the room "Don't tell me we missed something…"
Saria jumped over to the nearest platform "Doesn't something feel… Off, about this room?" she asked Alta.
Alta nodded in agreement, examining the features of the room "Yeah… It looks like the water's a bit discolored, huh?"
Saria looked at the water. She was right, the water here was a brighter blue than in the rest of the temple. She didn't see anything in it, though.
The others only saw what had happened next in the course of a single second - A tentacle, made out of the water itself, quickly shot up and grabbed Saria, pulling her off the platform and into the water. Sheik was the first to react, running to the edge of the water and grabbing Saria's arm before she was dragged too deep.
"S-Saria!" Alta called as she realized what happened, and the other two ran over to help Sheik "Hang on!" Saria would've answered, but her head was just under the surface of the water.
Malon spotted something moving through the water. Without time to think about it, she drew an arrow and fired at it, which chased it off. At the same time, whatever force was pulling Saria let go, allowing Sheik and Ruto to pull her up to solid ground, panting and coughing.
"Are you alright?" Sheik asked her. Alta flew to their side, as well.
"Y-yeah…" Saria answered, still coughing.
"Good thinking, Malon." Ruto said "What did you do?"
"I think I scared off whatever was controlling the water…" Malon replied "I take it that's Morpha?"
"Most likely."
"Stay on guard." Sheik advised, standing up while watching the water.
Malon pointed to something circling around in the water. It looked like a soccer ball-sized nucleus "There!"
Morpha created another rising tentacle out of the water, and swam up inside of it to get a better look at the intruders. What it saw were three Humans, one of them a small child, and a Zora girl. It did not recognize the symbol on Sheik's clothing, nor could it see the power of the Sages in Saria. Deciding they would be an easy threat to deal with, it swung the tentacle at them.
Everyone scattered and ran to dodge the tentacle. All succeeded except for Ruto, who was caught by it "Hey, let me go!"
"Uh oh, Ruto!" Saria called as Ruto was lifted into the air.
"Grr, I said let go!" Ruto yelled at it, giving Morpha a strong kick. As it was flung off by Ruto's attack, the tentacle fell to the ground, acting as regular water once contact with its controller was broken.
Malon ran over to help Ruto "Are you alright?"
"I'm fine."
Meanwhile, Sheik acted quickly, throwing a kunai at Morpha, who was bouncing back towards the water. It screeched as the blade grazed it, but it made it back into the water safely.
"That was good thinking, Ruto." Saria praised "How did you know to do that?"
"Oh, you know…" Ruto answered. Truthfully, she didn't; She was just flailing at that point "A princess has her ways."
Sheik rolled his eyes "I see…" He watched the water carefully for Morpha.
Morpha hadn't expected that to happen. The Zora girl was more aggressive than the others it had seen… Though it had been asleep for a while, so maybe this was normal nowadays. Either way, it had to be more careful, now that the intruders knew separating it from the water left it defenseless. It considered its options: It could just attack them in safety down here, but it couldn't see them from where it was. Moving up to where it could see them was too dangerous at this point, as it would have to travel up another tentacle to do that…
"Where did it go?" Malon asked, looking at the water along with Sheik.
"It's hiding." Sheik answered "Waiting for an opportunity to strike again, most likely."
"We can't wait for it to come to us." Ruto noted "I'll be right back." She dove into the water.
"Wha- Hey, Ruto!" Alta called "What are you doing?!"
Morpha was confused as it felt the Zora girl enter the water. Nobody had ever been bold enough to do that. It could feel her searching for it, moving swiftly through the water. While Morpha could certainly hold a Human in place in the water, like it did with the little girl, there was no way it was stopping a Zora. And while it could move fast in the water, she moved even faster.
Too late, the Zora spotted it. Thinking quickly, Morpha swam up to the surface, and created a long tentacle for it to swim through the air in so it could avoid the Humans' attacks.
Ruto had successfully chased Morpha out of the water. It used the water to move through the air with ease as it avoided her. Sheik's solution to this was to cut through the water, though Morpha had thought of that as well, and made several connections to the pool in the room to keep itself up in the air. Malon attempted to help by firing arrows at it, hoping at least one would hit its mark.
Saria had another plan, though. She gathered her energy into her sword, and waited for Morpha to come by the nearest water tunnel. As it swam by, she swung her sword horizontally, shooting a sword beam across the path of water. Unable to avoid this attack, Morpha was sliced in two, and the water fell.
The water slowly started to rise towards the ceiling, forming a sphere in the center, which slowly shrunk while drops of water fell to the ground. As the orb vanished, the last drop that fell transformed into the Water Medallion once it hit the ground.
The four of them climbed down the ladders on the sides of the platforms, making their way for the medallion. Once there, Ruto picked it up "What's this thing?"
"It's one of the Sages' medallions." Sheik explained "This one in particular is for you, the Sage of Water."
"Huh, really? So I'm a Sage, huh? I suppose it's only natural…"
"Hang on, how do you know that Ruto's the Water Sage?" Malon asked.
"I told you, I've done extensive research on the Sages."
"Why didn't you tell us this before?" Alta questioned "It would've been nice to know."
"You never asked, and the state of Zora's Domain was a more imminent concern."
"I guess that makes sense…"
"So, do you know who the next Sage is?" Now it was Saria's turn to speak.
"Yes, I do." Sheik answered "But first, let's get out of here."
"I can't argue with that." Malon agreed "This place is so confusing, I'll be so glad once we leave."
Saria and Alta nodded in agreement as well, while Ruto scratched her head "It's not that bad…" She mumbled to herself "Not when you know where you're going…"
"That was a nice shot, Saria!" Alta praised on the way back "How did you know to do that?"
"I just kind of came up with it on the spot, really." Saria replied "I saw that the nearest water path was horizontal, that Morpha was heading towards it, and the idea just… Came to me."
"Well, that was pretty cool, either way." Alta said, smiling.
Saria smiled back "You think so?"
"Yeah! You've improved quite a bit since you left the forest all that time ago."
"Ah, you don't really mean that…"
"Of course I do! Just because you still have room for improvement doesn't mean you haven't gotten better."
"That's true. Thanks, Alta."
"You're welcome."
