The ruins smelled like ash and static.
Kael stood on the scorched cliffside where the Watcher had fallen, its metal husk scattered like a broken marionette. All around him, his shadow flickered, restless. The battle had only confirmed what the Crystal Gems feared:
The Diamonds knew.
And worse, they remembered Black Obsidian.
"We should move quickly," Pearl said, scanning the sky with her spear raised. "This was only a probe. If White Diamond catches wind that her 'prototype' has returned…"
Kael's voice was low, but steady. "Then I'll face her."
Pearl flinched. Steven stepped in, his expression grave but calm. "You're strong, Kael. But not ready. Not yet. What did you tonight? That was incredible. But you barely controlled it."
Kael's brow furrowed. "What if I don't need control? What if I am the control?"
Garnet's visor shimmered with violet light as she spoke. "That kind of thinking leads to tyranny. We've seen it before. Power without balance corrupts."
Kael said nothing. But inside, something agreed with him. Something old.
Something watching.
They returned to the Temple, but Kael couldn't sleep. He wandered into the chamber behind the Crystal Heart — a sanctuary carved from luminous stone, filled with relics of the old wars. Rose's sword, Bismuth's forge tools, and shattered Gem shards in crystal coffins.
He stood before a mirror etched with diamond symbols and stared at his reflection. His eyes shifted in the light — black irises rimmed with violet. A faint pattern glowed beneath the skin of his chest, pulsing like a heartbeat. Like a Gem buried in flesh.
Then a voice whispered from within the mirror:
"You're close now."
Kael stumbled back, shadows lashing out instinctively — but the mirror didn't break. Instead, it rippled like water.
A doorway opened.
Behind it, nothing but black.
Kael stepped forward. Drawn.
He found himself in a cavern beyond space — vast, silent, and filled with floating obsidian structures. Glowing runes covered the walls. Towers of black crystal reached toward a skyless void.
This was no projection.
This was real.
He stood in the heart of something ancient. Familiar.
"The Shadow Cathedral," a voice echoed.
Kael turned. A figure emerged from the darkness — tall, armored in obsidian, with a crown of curved spikes and a Gem glowing in its chest like a dying star.
Its face… mirrored his own.
"I am what remains," the figure said. "You are what's next."
Kael stepped back. "Are you—?"
"Black Obsidian," the figure confirmed. "But not your father. Not anymore. A shadow of him. A memory preserved in this cathedral — your inheritance."
Kael's fists tightened. "Why am I like this? Why was I created?"
Obsidian's voice rumbled like collapsing mountains. "The Diamonds feared the dark between stars. They tried to weaponize it. I obeyed — until I became too powerful. So they scattered me across galaxies… and left the core inside a human. A hybrid."
"You," Kael whispered.
"You are not me," the specter said. "But you carry my Throne. My dominion. My army. They wait for you — beneath the earth, sealed in this realm."
Kael looked around. Dozens of shadow statues stood in formation, unmoving. Silent knights.
"Can I command them?"
"You already do," Obsidian said. "But command is not enough. You must become."
A pulse of energy spread from Kael's chest — the world around him trembled. And then, a throne rose from the floor behind Obsidian. Black stone, wreathed in violet fire. Ancient. Regal.
Kael stepped forward slowly.
"It is yours," the echo said. "Take it… or leave it. But know this — the Diamonds will not stop. They will come for Earth. For your friends. For you. And you must choose."
Kael looked at the throne.
Then sat down.
The cathedral awoke.
Statues cracked open. Eyes glowed blue. One by one, the shadow soldiers knelt before him.
His power surged — and this time, he didn't resist it.
Back in the temple, Steven gasped awake, heart racing, Gem glowing.
"Kael…" he whispered.
Garnet was already waiting in the next room. "He's made contact," she said.
"With Obsidian?" Steven asked.
"With the throne," Garnet confirmed.
Steven rubbed his forehead. "Then we need to make sure he doesn't lose himself."
Kael stood at the edge of the cathedral, eyes glowing, shadow cloak billowing behind him.
"Why me?" he asked softly.
Obsidian's echo stepped forward. "Because only a human could endure the burden. Only one with a heart could rule the void without becoming it."
Kael frowned. "And if I can't?"
"Then you'll become what they feared. A god of ruin."
Kael looked toward the exit — a swirling gateway back to the waking world.
"I'll be back," he promised.
Obsidian's echo bowed. "They will follow. Call when you need them."
Kael raised a hand.
The soldiers vanished into his shadow.
He woke up on the temple floor, breathing hard. Steven and Connie were beside him.
"You vanished for hours," Connie said, eyes wide. "Where were you?"
Kael looked at them.
Then slowly stood.
"I found my throne."