After some time, the patrol rotation changed. Tsuyu's team took its turn, then Yul's group came in to relieve them.
While that was happening, Yejin got called up to see the Grandmaster, leaving Kei and Vincent outside with the others, who were busy training in the courtyard.
The inside of the chamber felt cool and still, thick with the smell of sandalwood and old paper. Grandmaster Yoo Lingshu sat with his legs folded on a raised platform, his conical hat resting beside him. His narrow, piercing eyes locked onto Yejin the moment she stepped in and bowed low. He did not bother with small talk. "That Fabled Class group. Tell me again — what brought them all the way out here?"
"They're after the Heavenly Crystals," Yejin said. "As far as I understand it, the Gates of Abaddon out west have gone completely out of hand. More fiends keep pouring through, breeding faster than anyone can explain. I am afraid it's only a matter of time before it happens here too."
Lingshu looked away, out toward the sea through the tower window. "My teacher used to mention those crystals, back in the day. He told me it was better if I know nothing of them — that dark forces were hunting for them as well." His gaze did not waver from the horizon, like he was staring at something only he could see. "I knew my teacher well. He wasn't the type to exaggerate, or to scare easily. If he says it is perilous, the whole world must hold its breath." He breathed out slowly. "So no, I never let myself grow curious about them."
"I've never asked you this before, Master Yoo," Yejin said, maintaining a respectful tone. "But who exactly was your teacher?"
"A man of tremendous power. Possibly the strongest practitioner to ever exist. But then, one day, he was simply gone. Not a trace left. Khael and I parted ways not long after that. I remained here, dedicating myself to this tower, while he drifted toward the dark arts instead."
Yejin's eyes went wide. "Wait — you mean Khael? The Grim Warlock who put a curse on every woman in the empire? He trained under the same master as you?"
"Your father never mentioned it? But yes, it's true. In the end, I was the one who put a stop to him. But before all that, he was a fellow student — someone I once cared for deeply. I still don't fully understand what pushed him off the right path. Part of me still hopes he's found peace, even in the afterlife."
Yejin stayed quiet, absorbing everything, nodding slowly.
"Bring the two of them to my chamber," Lingshu said at last. "I want to see their eyes myself and decide if they can be trusted. That kind of trust doesn't come easily. Those crystals are the sort of secret better left buried than passed around."
"Understood. Thank you, Master." Yejin bowed once more and stepped out. Not long after, she came back, Kei and Vincent walking behind her.
The Grandmaster studied them closely, immediately sensing the immense power hidden beneath their calm exteriors. "There's a beast inside you, child. That cold — it clings to you," he said, eyes on Kei. Then his gaze shifted to Vincent, and his expression softened. "And you — full of fire. Warm. Alive."
Vincent smiled back easily, while Kei's expression did not change at all.
"I already know why you two are here so no need to explain further," Lingshu went on. "And I'll say it now — I won't be telling you anything about the crystals."
"B-but—" Vincent tried to protest, but Lingshu waved him off.
"No buts. You fail to grasp the gravity surrounding those crystals. My teacher was the one who guarded them, long before he vanished. After he was gone, no one heard a word about them again — not for decades — until the two of you showed up." Lingshu stood from his seat. "So be honest with me: what do you plan to do once you find them? The Goddess did not hide them away without reason — a very serious reason. If your motives are not clean, I'll prevent your organization myself, no matter the cost."
Worry crossed Yejin's face. "Master, please—"
"Yejin. Not now. This is between me and your two newest recruits," Lingshu said, cutting her off before she could finish.
She backed down without another word. Vincent looked caught off guard by the sudden sharpness in the old man's voice, while Kei just watched him, calm and unreadable.
Then, Lingshu snapped his fingers. The sound was small, almost gentle — and the entire room simply ceased to exist.
One moment there was stone and lantern light; the next, nothing. No walls, no ceiling, no floor beneath their boots. Vincent staggered, arms pinwheeling out of instinct before he realized he was not falling. He was standing.
"Where'd everything go?" he asked, spinning in a slow circle. Gray water stretched in every direction, flat and endless, meeting a horizon that seemed to bend at the edges of sight. The surface did not ripple under his boots. It did not give at all — like glass pretending to be water, holding his full weight without so much as a shiver.
"This must be one of Grandmaster Yoo's abilities," Yejin breathed, turning slowly, taking it all in. "Something beyond what most people could ever grasp." Her voice had dropped, almost reverent. "Unless I'm wrong, this is a pocket dimension! Only a handful of practitioners can even create one, let alone hold it steady this long. I've heard stories about them my whole life. I never thought I'd actually stand inside one."
"Don't worry yourselves," Lingshu said. His voice came from everywhere and nowhere, and when he appeared, it was as though he had simply always been standing there. "I call this place the Timeless Chamber. I brought you here to see what really drives you." His eyes settled on Kei, and the corner of his mouth curled upward. "Though I suspect this young man already understands what I mean. I can feel it — that cold beast, curled up somewhere inside him."
"Kei? What's he talking about?" Vincent glanced sideways at his companion.
Kei exhaled, slow and deliberate, and his eyes kindled into a pale, ghostly blue. "Pocket dimensions aren't something you learn easily. You're either born with it, or you spend decades clawing your way toward one." A pause. "Mine came with birth." He studied Lingshu now with something close to reverence, the closest thing to genuine respect Vincent had ever seen cross his face. "But stretching one across all of reality — pulling other people's minds inside it with you — I never thought that was possible. You may be the strongest practitioner I've ever stood in front of. Even more powerful than Lady Sora."
The water convulsed.
It happened without warning — a violent shudder that rolled beneath their feet, followed by a growl so low it seemed to come up through the soles of their boots rather than through the air. The false ocean rippled outward in widening rings, and for one heartbeat, something vast shifted just beneath the surface.
"What was that?!" Vincent's flame guttered against his skin, his whole body going rigid. Beside him, Yejin had gone pale and still, a chill crawling up the back of her neck.
Lingshu only smiled, patient, watching the water the way a man watches a pot he knows is about to boil. However, whatever waited beneath never broke the surface. Kei would not let it.
"Something wrong?" Lingshu asked mildly. "Calling out your familiar would make this considerably easier on you, you know."
"Familiar?" Yejin's brow furrowed.
"Ah — so that's what that was." Vincent's eyes lit with understanding. "Didn't know you had one, Kei. What else are you hiding from me?"
"What's a familiar?" Yejin asked. "I've never even heard the term."
"Immortal spirit beasts," Vincent said, "bonded soul-deep to their masters. Nothing like the flame serpent I summon — familiars are a different tier entirely. They fight beside you like an extension of yourself, and they've got their own mind, their own reserves of prana and mantra." He glanced at Kei, thoughtful. "Didn't realize a pocket dimension might be tied to that kind of summoning. Guess I'm learning something new too."
Lingshu said nothing. The tremor beneath the water faded into stillness, and Kei's shoulders loosened by a fraction, that flicker of restraint settling back beneath his usual composure.
"If you'd rather keep it caged, that's your business," Lingshu said. "Then we'll do this the harder way. The two of you, against me, for ten minutes. Survive that, and I'll tell you what I know about the crystals — some of it, at least."
"Huh? Doesn't sound like much of a trade," Vincent said. "For all we know, what you'd tell us isn't even worth the bruises."
"Ha! Sharp tongue on this one." Lingshu's eyes glinted. "Though I don't recall offering you a choice in the matter."
Vincent's smirk returned, easy and unbothered. "Fair enough, when you put it that way."
Lingshu turned to Yejin. "Stand back, child. Watch closely. I have a feeling this is about to get very large, very fast."
His cloak slid from his shoulders and vanished before it touched the water. "Well? Are you ready?" A low chuckle escaped him, mischief flashing behind those sharp old eyes. "Don't go underestimating me just because of these gray hairs. Old doesn't mean slow."
Fire raced up Vincent's arms, wrapping his forearms in twin sleeves of flame. Beside him, Kei's Deathsight bloomed to life, his irises flaring an electric blue as he raked his gaze over every inch of Lingshu's body, searching — and finding nothing. Not one weak point. Not one opening. The realization settled into his chest like a stone.
"Vince... be careful. He doesn't have a single vulnerability at all." Kei said, leaving Vincent in silent shock.
"Then let's begin," Lingshu said.
Behind him, the ocean answered first. It rose — not in a wave, but in a wall, climbing higher and higher until it blotted out what little light there was, its shadow falling over all three of them like the closing of a great, dark door.