They stood before the sealed chamber of the No Life King.
Kaito held the key Grigori had given him as a profound suspicion gnawed at him. "...Why does Grigori have the key to his own prison?" he muttered, more to himself than to the others.
'Indeed, that is a mystery,' Durandal shared the suspicion. 'It should be guarded by the Church at all times, yet he was able to get his hands on it. What exactly happened to the Church's vigilance here?'
Kaito clenched his hand, the key digging into his palm. He turned to Tamamo and handed her the key. "I'm going to go all out and finish this as soon as possible. Tamamo, can you open the door for me? Eleanor, stay safe in the back."
With a nod from his companions, Kaito summoned Durandal. He tiled the blade as the entirety of the brightly lit prison was instantly engulfed in darkness. The floating lamps went out, and the glowing cell bars winked into non-existence. Some of the sleeping inhabitants woke up, their eyes—be they human, monstrous, or supernatural—opening to look in Kaito's direction. In this new world of profound colorless darkness, Durandal was the only source of light, a beacon of holy energy.
"Now, Tamamo!" Kaito commanded.
Tamamo nodded, inserting the key into the cell door of the No Life King. The ethereal bars of light shimmered and vanished.
"Full Resonance!" Kaito roared and vanished.
A powerful force shook the entirety of the prison. Durandal was plunged directly through the skull of the No Life King, the impact creating a large crack on the wall behind him. The burning soul flame within the No Life King's eye socket flickered and died down with a mournful, creaking rasp. The skeleton's body went utterly still.
Kaito deactivated Full Resonance and pulled Durandal out, leaving a radiant trace of holy energy on the cracked skull.
Believing the mission accomplished, Kaito turned to leave. However, he was stopped by a low, crackling sound, followed by a sudden, sinister laugh. The low laughter increased in intensity, the sound of cracking getting louder and closer. Kaito turned back to witness the glowing chains binding the No Life King's skeleton cracking, then completely shattering with a flex of the skeleton non-existent muscles.
The skeleton threw its head back, its empty socket glowing with a renewed, fiery soul flame. "Hahahaha! Rejoice, boy! You have achieved your mission... of freeing me!"
Kaito's eyes widened in horror. He immediately swung Durandal, intending to strike at the reanimated lich. However, the skeleton simply held out a hand and muttered a spell: 反轉界域 (Fǎn Zhuǎn Jiè Yù). A ripple of black energy surged outward.
Not just Kaito, but Eleanor and Tamamo were also immediately crushed under its weight. Their strength evaporated, leaving them gasping for breath. The very air became poisoned with undeath, and the once negligible aura of the No Life King was now overwhelming as it saturated the space like tar.
Kaito, struggling to breathe, summoned Shikabanehime. He cycled her power through his body, and with an immense effort, pushed himself back up to one knee. Just then, Grigori appeared beside the No Life King, a smug, knowing smile on his face.
"Did you really believe I gave you my blessing to aid you?" Grigori sneered. "How naïve."
The No Life King laughed, a dry, rattling sound. "In this eternal prison, I've had endless time to study the very nature of holy magic. As an undead of pure darkness, the brilliance of holy magic was my nemesis. Yet, through endless research, I've found an equilibrium of light and dark. All I needed was a large, concentrated injection of holy energy into my immortal vessel—something I couldn't provide or extract myself due to my oath and circumstances."
"As I said," Grigori continued, "the Order would have worked for my plan, as they would undoubtedly have used holy magic to strike my immortal vessel down. You were just an unexpected pawn that set my plan ahead of its motion."
The No Life King raised his hand, an ominous black orb of energy forming in his palm. "As my final act of gratitude toward you, I shall send you off with a quick and painless death."
'Master, get up!' Shikabanehime's voice screamed in Kaito's mind. She was working frantically, draining her life-force reserve collected from the trees earlier, but it wasn't enough. Kaito remained on one knee, struggling to rise against the crushing spiritual pressure.
A flying talisman from a struggling Tamamo came flying at the No Life King, but he casually swatted it away. The ominous orb began to launch towards Kaito.
"Full Res-" Kaito was about to roar, but a hand suddenly clamped down on his shoulder. With a heavy, metallic footstep, the armored figure appeared in front of Kaito, deflecting the black orb with its gauntlet.
"Needless to say," the suit of armor boomed, its voice echoing, "You should've heeded my words."
"The Knight of Pitch-Black Soul," Grigori said, narrowing his eyes. "So you decided to interfere. You were always the righteous one, despite your soul being the polar opposite."
"And yet," the knight replied, "even a blackened soul can recognize evil."
"So, this's what you were up to," the knight continued as he looks at Grigori. "I thought you launched your phylactery deep into the cosmos, but it seems you kept a backup plan."
The oppressive aura was lifted. Kaito and the other gasped, finally able to breathe as they unsteadily got back on their feet.
More figures emerged from the corridor.
The No Life King looked around at his former inmates, his burning eyes filled with a furious disbelief. "Why are all of you freed, and helping him?"
The vampire smiled coldly. "Did you not notice? His early attack weakened our seal for a brief moment, allowing powerful beings like us to escape."
The fallen angel stepped forward with a melodic laugh. "Don't look so surprised. You wanted an audience, didn't you?"
"Nevertheless," Grigori said, attempting to regain control of the situation, "it would have taken an enormous amount of your power to escape. You're no match for me."
"Really," the fallen angel sneered, his black wings stretching slightly, "even with me here?"
The bearded man opened his eyes for the first time, his gaze ancient and full of wisdom. "No Life King, although you now have eyes, you still fail to see Mt. Tai."
A deep tremor followed his words as a towering figure blocked the corridor entrance. The giant silver dragon spread his wings, scales shimmering like moonlit metal, as its head peered in from the corridor.
"It's nice to stretch my wing again," it rumbled.
The No Life King looked from the dragon to the fallen angel to the rest of the powerful beings, and then back to Kaito. "Durandal's chosen... it seems today is your lucky day. I shall let you live a moment longer."
With that, both the No Life King and Grigori disappeared from the cell, leaving a tense silence in their wake.