03/06/24 - This chapter contains author's notes at the end

The domain's interior was quite different from what Phos imagined, although, to be honest, anything could've been vastly different from whatever they would have even imagined. To begin with, the gem couldn't have imagined the weird blue portal outside the ruins would take them to an indoors location; a long, tall corridor extended in front of the trio, its walls decorated with rich symbols, despite the lack of windows, there was an odd, almost unnatural light that illuminated their path.

"What a view" Kaeya whistled, although his expression wasn't particularly surprising. "When was the last time a domain popped out nearby the Thousand Winds Temple?"

"I'd imagine you knights have better records of such incidents than I do." The redhead muttered, arms crossed as he walked besides the blue-haired man. "But if you insist on asking me… I'd say it's been quite some time, and last time I hadn't heard of the Abyss Order getting involved, it'd make sense for them to take advantage of a domain that hasn't showed recent activity to use as a temporal base."

"What is that Abyss Order, anyway?" The gem interrupted as they squeezed themself between the two males. "Everybody mentions them as if they're a big deal… but what are they?"

"I'd suppose that's because they are a big deal." Kaeya let out an awkward chuckle as he scratched his cheek, at which Diluc huffed, visibly annoyed, or so thought Phos.

"The Abyss Order hates everything and everyone who lives under the sun, as they consider them to be under the Archons' blessing, and most of their members come from a long-time fallen nation that stood against them. I haven't been able to make them spill their true intentions, but they are a constant threat to the seven nations." Diluc explained, although he seemed calm, his voice was severe, almost resentful.

Phos only nodded in understanding, they could assume this Abyss Order was for the people of Teyvat what the Lunarians were for the gems, perhaps on a bigger scale? Human things always felt so complex for them.

They kept walking forwards, as the corridor seemed to not have other entrances to explore, and the only few barrels and boxes scattered had long forgotten provisions. The only remarkable thing at the moment seemed to be the weak light coming from the end of the corridor, at which the trio agreed to keep on walking, the only sound accompanying them was the echo of their footsteps as they kept moving.

"Huh, that's odd," Kaeya mumbled as he rubbed his chin. "They usually summon hordes of hilichurls to guard their bases."

Judging by Diluc's uneasy expression, Phos would have to give the cryo user the reason. Even they felt something was wrong, somehow. As they got closer to the end of the corridor, the light welcomed them to a wider place. It seemed like a big, square room, unlike the corridor, it had no roof, and a beautiful starry sky could be seen above them. The central part was some meters below everything else, and an odd cubic shaped device rested in the middle, it seemed to be protected with red strings of energy. On the sides, stone railings guided to three separate rooms. Some minor wooden structures rested half-destroyed, scattered across the space.

"Just how long have they been here?" Diluc's concern seemed to grow as they walked downstairs to the cubic device. "This seems to be well-planned…"

"The domain didn't show up until some days ago, perhaps they used some sort of magic to hide it for some time." Kaeya suggested as he kneeled to inspect the floor. "Whatever they're planning, my guess is that we'll find it up there." The cavalry captain pointed to the starry sky. "This seems to be an elevator of sorts, if we can find a way to unlock the device, we could go up and take a look."

"There seem to be more rooms connected to this one, perhaps we'll find our solution there." Phos said as they walked towards the nearest room, the one on the left. There were a few boxes arranged in a way that seemed to poorly hide something among them. With a strong swing from his claymore, the gem destroyed them, finding another device like the one on the central hall. Perhaps if they turned it on the other one would get unlocked. "I found one!" The gem said as they looked at it, now that they thought about it, they didn't know how to activate it. Phos stretched their hand to touch at its sides, looking for a way to move it, when they reached the luminous square in the middle, it was too late for them to hear the voices outside the room.

"Wait…!"

When Phos turned their head towards the room's entrance, all they saw were both males rushing towards them, only to be stopped by a stone door that locked the gem inside. Panic took over the gem, as they ran towards the door, trying to open it with no success.

"H-hey! Oh… oh no…no good"

Panic only increased as several shapes began to appear between a familiar dark mist. Blue, blob-shaped creatures emerged from it, they only had eyes, and their round shape made them even look strangely cute. The peppermint-colored gem even considered lowering their guard until one of the creatures bumped them on the leg, making them almost stumble backwards. Ok, they weren't friendly.

Phosphophyllite lifted their claymore and swung it against the creatures; one, two, three swings until they effectively disintegrated in a slimy puddle. Before the gem could relax, two more of them appeared, these were bigger. Although the smaller ones hadn't caused them any significant damage besides removing part of the powder on their face, Phos felt the bigger ones were strong enough to break them. They gripped their claymore, preparing for another swing, the big blobs tried to bump them whenever they got too close, and they almost crushed them a couple of times, yet somehow the gem managed to turn out victorious. They swept part of the slime from their boots, its sluggy texture reminded them of Ventricosus, although something told them these creatures, unlike the King, were not particularly organic nor fleshy. Much to their relief, the door finally opened, effectively setting Phos free.

Outside, in the main hall, the gem was greeted with both of their companions amongst traces of the black mist that showed whenever an enemy got defeated. Once they noticed their presence, their posture seemed to relax, although Diluc seemed even more annoyed than before, at least for a second.

"Don't… do that again", the redhead huffed, letting his claymore rest on his back. Unlike him, Kaeya seemed a little less bothered, although the concern on his face was visible.

"At least not before telling us. I'm glad to see you're fine." The tanned man hummed, relieved. "Anyway, it seems whatever you did helped, look." he said as he pointed towards the main device, effectively, one of the energy strings had vanished, leaving two to take care of. "When you activated the secondary device, it seems it started a test of sorts, I'm glad to see our training sessions had worked." He chirped.

"Still, it was reckless of you." Diluc interrupted, arms crossed once again. "Now we know that, whenever we activate one of those devices, enemies appear both outside and inside the room, that's weird, it seems as if they purposefully want to split us, but why?"

"No idea, but neither are they bringing us particularly tough enemies, anyway, we just fought what could be your average hilichurl camp, and Phos looks as if they had fought some slimes."

"Is that how they're named?" The gem's question only confirmed Kaeya's guess. "I… suppose they are easier to fight than a hilichurl". Phos watched as Kaeya gave Diluc a look, as if silently telling him not to worry. The redhead let out an annoyed gruntle before leaving the topic behind.

"Alright, then I suppose we can do this a couple of times more, okay?"

It seemed as if Kaeya's observation wasn't wrong. The trio repeated the same tactic they used with the first device, leaving the vision wielders outside to face the bigger foes as Phos took care of the smaller ones that appeared inside the side rooms, effectively, only slimes and an occasional hilichurl appeared, making Phos's task relatively easier. Still, these trials proved to let the gem learn more things on how this world worked. For example, they were sure to be extra cautious with the red and purple slimes, as they seemed to be made of pyro and electro, elements Phos learned that could be highly volatile when mixed; the least they needed at that moment was to shatter again.

During the last room's trial, they encountered mostly earthly-colored slimes with rock-like structures on their heads. They seemed tougher, but Phos soon realized they were especially brittle when they got rid of its rocky cover. Could this be how lunarians felt when they took their kind to the moon? They chose to vehemently ignore that thought for their own sake.

Just as they finished off the last slime, the room opened, allowing them to return to the central hall. There, their two companions were just retreating their weapons, it seemed as if they hadn't either struggled with whatever enemy they had to fight and, except from Kaeya's slightly singed fur cape and Diluc's coat sprinkled with frost, both men seemed mostly unharmed.

"Good job, Phos!" The cryo user said, placing knew hand on his hip as he fixes his cape with the other. "It's good to see our training has worked nicely, perhaps I could arrange some training outside the city next time…"

"Better think about that later." The redhead huffed, brushing off some of the tiny cryo crystals still on his coat. "It seems that was the last one. We should be able to turn on this one now. If our hypothesis is right, our objective is up there." He clarified, pointing towards the starry sky that rested above their heads. "I still have a very bad feeling about this, but I doubt we'll have another chance if we retreat now, sure you Knights wouldn't bother on making a proper investigation once we leave."

"Haha, why the sudden rudeness, Master Diluc? We were doing so nice…" Kaeya waved a hand in a dismissive gesture. "Although I can't guarantee a quick aid, as you must remember, we're grossly understaffed due to Grandmaster Varma's expedition." He let out a tired sigh. "Nevermind, we should hurry, whatever awaits us, we shouldn't keep it waiting."

"Alright…?" Phos still found it rather awkward to be stuck in the middle of the men's constant bickering, but it seemed they were doing it mostly out of habit. It reminded them a little about how Morga and Goshe would sometimes bicker between each other before their patrols.

Nevertheless, they activated the device in the middle of the hall. It lit up, causing the ground to grumble as an squared zone got illuminated as well. Soon, the three of them felt the platform they were standing on began to move upwards, leaving the hall with the three rooms below them.

As the elevator kept moving upwards, the sky seemed to get closer, until it surrounded them as they found themselves on the top of what seemed like an ancient fortress. Another ruins were vaguely noticeable nearby them, and a pale fog extended beyond the ruins, making everything look as if they were in a misty ocean.

"You've finally arrived, enemies of the Abyss" An otherworldly voice came from behind them. Phos turned around just in time to see how both men unleashed their weapons as a bigger creature emerged from a portal. Its vaguely humanoid shape easily towered both Diluc and Kaeya, its clothes were also strange, red with intricate details, and its head seemed also oddly shaped, as if it wore a horned helmet, although Phos couldn't decipher whether it was a helmet or the creature's face. "It's a shame you have come only to meet your demise!"

At that, the creature summoned a strange, star-shaped object that floated on one of its hands, it spinned as flames began to emerge from the ground.

"Careful!" Diluc warned, rolling aside just in avoid one of the flames. "Ugh… I hate those bastards." The redhead mumbled, it wasn't his first time facing one of them, and so he knew how theatrical their antics could be while still being a bigger threat, moreso as this one was able to control his same element, which put him at a heavy disadvantage.

"This is bad" Kaeya scowled, also moving aside to avoid the Abyss Herald's attacks. "I don't think my vision will suffice." He complained before throwing a cryo attack at the enemy, although it seemed to work, the reaction was considerably weaker than what Phos had expected to see.

They really wanted to help, they had improved over those past weeks haven they? Then… Why did their feet not move? They stood frozen in their place, clenching their claymore as they pondered how to act next.

"It is futile, no one can oppose the Abyss Order!" The Abyss Herald casted a spell, and more fire columns emerged around it, one of them effectively hit Diluc, and although the man tried to resist, its force was enough to push him near the edge of the roof.

"Diluc!" As he saw the tycoon still standing, albeit a little disoriented, Kaeya released a sigh, okay, he needed to be careful. As more flames came towards him, the blue-haired man spinned on his heels, using his vision to neutralize some of the flames as he moved towards the Abyss creature. However, just as he was about to reach it, the monster teleported a few meters away, casting fire balls that were launched directly at the Cavalry Captain. "Augh!" Kaeya hissed in pain, being forced to retreat.

"So annoying…" Diluc muttered, tightening the grip on his claymore, if only he could get close enough to the damned thing, he'd crush it with his bare claymore, no pyro needed. If only it could be as easy as that, he lamented.

Meanwhile, Phos had remained mostly aside from the battle, only trying to evade the pyro columns the better they could. Seeing how easily those attacks had pushed aside their companions only made them worry the more. What was he thinking? They came to help the knights in their research to help them find a way back home, they couldn't just sit back and let the two men deal with all the hardships of the encounter!

Pulling out their claymore, the gem rushed towards the Herald, evading the fire columns as best as they could, still, just like the creature did with Kaeya, it teleported when Phos was a few steps from it. The gem rolled aside, barely avoiding the fire balls thrown at them, they could feel the stress their body was being subjected to, clearly uncomfortable with the environmental temperature. Still, they didn't retreat, rolling forwards before stretching their golden alloy to catch on the Herald's legs.

"You…! Move aside!" The monster threw a bigger attack towards Phos. What looked like a tiny particle emerged from the ground below them, it grew slightly before exploding in a fiery attack that Phosphohpyllite barely evaded, although their leg began to crack.

"No good," They thought.

They kept tightening their grip on the Abyss Herald, their alloy beginning to engulf its lower part, effectively pinning it against the floor. More golden tendrils extended towards its arms in an attempt to immobilize it. The creature shrieked in confusion, unable to flee, but still able to fight back, it summoned more of those pyro explosions. Bigger, more aggressive-looking cracks appeared on Phos's body, yet the gem didn't stop.

"I got him! Quick!" They yelled at their companions.

Both men stood visibly stunned, although both had heard of and witnessed a glimpse of Phos's display of skill at using their golden alloy, this was the first time they had seen it at such an extent. The gem's words took them by surprise.

"No way! It 's too risky!" Diluc yelled,knowing that if they attacked the herald, Phos would likely get severely injured by the attack.

"I don't think there's another way… quick…!" They had secured themself to the floor with the help of the golden alloy in an attempt to resist the Herald's attacks. Even though they felt afraid of how badly they could get broken, it seemed to be their only way to defeat the creature.

Kaeya pressed his lips in a straight line before sighing, defeated. "What a bummer, let's do it quick" He reluctantly lifted his sword, his vision lightened as he concentrated cryo on his hands. Diluc did the same, lifting his claymore and imbuing it with pyro as he prepared to release his attack.

Icicles surrounded the cavalry captain, as he ran towards the trapped herald, his swings became stronger, and the icicles surrounding him cooled the environment, easing the scorching feeling.

"Move aside!" Diluc yelled, the pyro in his claymore lit as a bird-shaped flame appeared. The tycoon threw his attack at the herald.

Pyro flames rushed towards them like a fire wave, all that Phos could do was to close their eyes as they anticipated the impact. However, they felt oddly at ease, as if they knew their action was not in vain.

Suddenly, a bright light surrounded them. It wasn't the red and orange flames that came from Diluc's attack, instead, this light was purer, and felt as if it was coming from within them. Nervous, they opened their eyes, glancing upwards. Everything felt as if it was happening in slow motion. For a moment, the gem was able to briefly look at a familiar-looking place for them; the school seemed oddly quiet. They could see Sensei overlooking an even smaller number of gems as they reassigned tasks to fulfill, their view zoomed out until they could see the big piece of land where the school was. The lack of several of them made them wonder if more gems had landed on Teyvat, where couñd they be, anyway? Their view went even further, looking at a pretty blue-colored orb in the middle of the stars. Perplexed, they blinked once, twice until they realized they were still inside the odd domain.

The starry sky greeted them, a bright, turquoise comet could be seen crossing the sky, and a warm voice could be heard from seemingly nowhere.

The will of Celestia acknowledges your ambition, child of the bones. Be not afraid.

The voice felt so reassuring that made Phos lessen their nerves, even though Diluc's attack was still going towards them. The peppermint-colored gem closed their eyes, somehow, they were no longer afraid of whatever could come next.

To say both men were shocked was an understatement. Diluc, who had just been practically forced to agree on taking down one of his teammates so they could finish off a bigger threat was now holding his claymore with such strength that his knuckles ached. He knew it was a bad idea, he shouldn't have trusted Kaeya on any of this.

Speaking of whom, the blue-haired man lacked his usual smile, now replaced with a concerned scowl. He tapped his foot against the stone floor as the smoke raised by Diluc's attack dissipated. In the meantime his mind was already planning which words would make Jean the least concerned when he returned.

Neither of them expected that, once the smoke had fully dissipated, they'd be greeted with a blinding light, as bright and familiar as they could remember. Both gasped as they looked at the cubic-shaped structure shielding Phosphophyllite, the traces of what once was the Abyss Herald slowly disintegrating, sometimes bumping against the translucent surface. What shocked them the most was, however, the gem-shaped object that rested on Phos's hands.

It seemed they really did need to visit the domain to get something of interest for Phosphophyllite's situation.

Author's notes:

We've finally reached the same chapter that it's currently published in AO3! I'm currently working on chapter 10 but it will take at least a couple of weeks more to get out as I'm currently a couple of weeks from finishing university. I'm very thankful for all the support this story has gotten on both platforms.

Now, I'll make the same question I made on AO3. Which vision do you think Phos got? I have more or less an idea of which one I'll give them but I'm curious to know your ideas.