The morning after the Nightborn attack arrived without sunlight.
The sky was grey, heavy with ash and uncertainty. Leo no longer shimmered overhead. Instead, a smudged veil of clouds and dim stars lingered above the observatory — as if the heavens themselves were wounded.
Erza sat alone on the cliff ledge, the wind tugging gently at his cloak. His skin still pulsed with the residual heat of yesterday's flame, but his heart felt cold. That thing — the Nightborn — had nearly broken them. And it had worn a face. A human face.
Were they once like him?
"Thinking won't stop them," came a voice behind him.
Selene stood with arms folded, her shadow long against the rocks. She never asked how he felt. Never coddled him. That was why he trusted her more than most.
"I'm not thinking," Erza muttered. "I'm listening."
Selene tilted her head. "To what?"
"To the stars," he said, closing his eyes.
For a moment, there was nothing but silence.
And then — something answered.
A voice not spoken, but felt. Ancient, feminine, warm like a hearth fire. It echoed from deep within his soul — as though the Leo constellation itself had taken breath.
"Erza Black. Son of fallen flame. Bearer of Leo. We hear your roar."
His eyes snapped open. The stars had returned — faint, distant, but aligned. Not above.
Within.
Erza rose, startled. "Did you hear that?"
Selene narrowed her eyes. "No."
"I think… something's calling me. Not from the sky. From the Vault."
Caelum, who had just emerged with a scroll tube, froze at the word. "The Celestial Vault? That's impossible. It was sealed centuries ago, after the last Starfall War."
Erza turned to him. "Then it's time someone reopened it."
Lyra stepped forward from the shadows of the observatory. "Do you even know where it is?"
Erza nodded slowly, placing a hand over his chest. "Now I do."
The Celestial Vault was not a place.
It was a memory — a buried sanctum woven into the folds of the Astral Veil, accessible only through resonance. Carved between space and starlight, reachable by those bound to true constellations.
The team descended into a forgotten cavern system beneath the observatory, guided by Erza's intuition — or perhaps something more. Every wall pulsed faintly with astral lines, glowing only when he passed.
At last, they reached a chamber where the ceiling arched like a cosmic dome and a star map shifted overhead, alive.
At the center stood a single figure.
She was unlike anything Erza had ever seen. Draped in radiant robes stitched from pure stardust, her skin shimmered like the void between galaxies. Her eyes — two burning golden orbs — locked onto his.
"Leo has chosen," she said. "The flame roars once more."
Erza stepped forward, cautious. "Who are you?"
"I am Aethera, Keeper of the Vault. Last Sentinel of the Constellation Hosts."
Caelum gasped audibly. "Those were myths! Guardians chosen by the stars to channel their true essence!"
"Not myths. Just forgotten," Aethera replied. "Like your kingdom. Like your bloodline. But now, the stars awaken — because they must."
Raze crossed his arms. "What do you mean must?"
Aethera turned toward the moving constellations. "The Nightborn were not created. They were unbound. Once, they were Constellation Hosts like you — chosen. But when the stars began to fade during the Great Collapse, they sought power from the dark between constellations. From Unlight. They devoured their bonds, twisted them. And now, they seek to devour what remains."
Selene's voice was a whisper. "They're not just hunting us. They're hunting the sky."
Erza stepped forward, fire rising in his chest. "Then how do I stop them?"
Aethera raised her hand, and a brilliant flame formed in her palm — no longer ordinary starlight, but a dense orb of Living Constellation Flame.
"You must complete the Rite of Resonance. Align your soul fully with Leo. Only then can you wield its full power — not just its fire, but its will. And with it, call the Eidolion."
Lyra's breath caught. "You mean the Astral Beasts? The original guardians of the stars?"
Aethera nodded solemnly. "They slumber. But one — the Celestial Lion — still stirs beneath Duskfire's ruins."
Erza took the flame. It didn't burn him. It recognized him.
"You are not ready to win," Aethera said. "But you are ready to begin."
Erza met her gaze, calm now. The fear hadn't vanished — but it had somewhere to go.
"I'll take the Rite. I'll summon the Celestial Lion. And I'll remind the stars why they once followed kings of fire."
As the others watched, the celestial flame blazed behind him — and far above, in the distant sky, Leo began to roar again.
The war was no longer about vengeance.
It was about salvation.