In his mental realm, a vast, clean catacomb stretched out before Kaito. The polished stone floor and towering pillars gave the space an almost sterile, oppressive feel. At the far end, upon a throne of pure platinum, sat the No Life King. The skeletal figure was a chilling mirror of Grigori's sealed vessel, but this one was a king, not a prisoner. A great scythe with a wickedly curved blade rested beside him, its edge humming with unseen malice.
Kaito was fighting a seemingly endless army of undead. Death Knights in prestine armor, spectral wraiths, malevolent liches, and countless skeletons surged toward him. Kaito cleaved through the lesser undead with ease with Durandal. He spent more time clashing with the cunning Death Knights and dodging the intricate spells of the liches, learning the patterns of their attacks.
But it was all a prelude to the true enemy. Kaito had already become acutely aware of the No Life King's most insidious spell: an inversion-type magic that flipped the benefits of any positive buff and doubled its negative effects. Kaito's passive abilities, meant to mitigate negative influences, were useless against it.
He recalls the lingering effects of Grigori's earlier "blessing" was a constant, invisible shackle, a positive effect that would cripple him the moment it was inverted. He couldn't adapt to the No Life King aura with Shikabanehime's ability in this mental realm, as it lacked the physical and spiritual feedback loop of reality. To make matters worse, the No Life King had researched a way to mitigate his own weakness to holy energy. Kaito's most powerful attacks, which channeled Durandal's holy light, were no longer a guaranteed victory. The true battle with the real No Life King seemed hopeless.
Frustrated at the thoughts, Kaito once again flew directly toward the platinum throne, a single-minded assault to end the battle before it began. He was halfway across the catacomb when he felt a sudden, immense pain in his heart. It was a searing, crushing agony that made him cough up a mouthful of blood and sent him plummeting to the ground. He looked up, his vision blurring, and saw the No Life King holding a manifestation of his physical heart in its skeletal palm, which it then crushed without a second thought.
Kaito was reset. He found himself back at the starting point, but this time, he simply laid on the ground. The endless darkness of his own mind seemed to press down on him. The No Life King, in all his intellectual malice and power, felt like an unbeatable, insurmountable force. And Kaito was the one who had helped him escape. The guilt was a heavy, suffocating blanket. Despite knowing that the Order may have eventually unleashed him without his involvement, that didn't change the fact that he was the instrument of his freedom.
"Master, it's not your fault. You were tricked," Shikabanehime said, full of worry.
"She's right, Kaito," Durandal added, her tone firm but gentle. "He exploited your nature for his own benefit. The burden of guilt also falls upon me, as I failed to see pass his deception."
Kaito slowly sat up, running a hand through his hair. "Don't blame yourself, Durandal. It was my decision, and I shall make amends for it." He looked into the void, the crushing weight of his failure heavy on his shoulders. "It's just... how am I supposed to defeat him? The No Life King seems to be unbeatable."
"There is one option," Durandal said after a long pause of hesitation. "But I'm not sure you're ready to use this technique."
"I would like to hear it out regardless of the danger," Kaito said, his resolve hardening.
"You can temporarily fuse with me, inheriting my indestructible properties," Durandal explained. "However, I fear that you might be corroded by my connection with Heaven and the Almighty, and in turn, lose your humanity as a result. You would become an emotionless entity who prioritizes logic above all else. You would need to be much stronger than you are now and hold an overwhelmingly powerful emotion to overwrite it."
Kaito was silent for a moment, weighing the cost. "Would I be able to defeat the No Life King if I were to temporarily fuse with you, Durandal?"
"It is uncertain," Durandal admitted, "but in that fused state, I have not known defeat."
"Then, it's enough for me to at least try it," Kaito said, a flicker of his former defiance returning.
"...What if I were to also be fused with master?" Shikabanehime's voice, a quiet but firm presence, joined the conversation. "Would my curse nature balance out your connection to Heaven?"
"That's possible in theory," Durandal replied, "I have been fused with other weapons and relics before. However, you will most likely be purified of your curses if you are exposed to the connection of Heaven for an extended period of time."
"That wouldn't be a problem," Shikabanehime stated without hesitation. "If it's to help master, then it is only natural for me to do so."
A small, genuine smile touched Kaito's lips. "Thank you..." he whispered, his gratitude overwhelming. After a long pause, Kaito stood up, his posture straight and his gaze determined. "Please teach me how to do this, Durandal."
"Very well." Durandal held onto Kaito's right hand with both of hers. Shikabanehime followed and did the same to his left. "Fully resonate with her as you have resonated with me."
Kaito closed his eyes, concentrating. A rhythmic, powerful connection coursed through him, a harmony of light and shadow. "Now, allow ourselves to encompass you as one. Allow our souls and minds to connect, and to harmonize with us."
The landscape of his mental realm began to shift wildly in an unstable rhythm. A blinding, holy light erupted from one side, while the other remained cloaked in an endless, suffocating darkness. The two realms pulsed, appearing and disappearing, flipping sides with a chaotic energy that threatened to tear Kaito's consciousness apart. Amidst the chaos, a massive, vibrant red and black sakura tree materialized, its roots digging deep into both the light and the darkness, trying to bridge the gap.
Kaito held on, embracing the chaos, letting the opposing forces wash over him. He allowed the light to purify his doubts and the darkness to ground his resolve. Slowly, the two halves of the landscape began to stabilize. The blinding light softened, becoming a brilliant, overwhelming radiance that shone brightly upon the sea of darkness that formed the ground. The single red and black sakura tree grew, its petals falling like delicate drops of blood and shadow.
When the transformation was complete, the forms of Durandal and Shikabanehime had disappeared. Kaito stood alone, but he was no longer the same. His hair, once a simple black, was now much longer, reaching halfway to his waist. Its color was a chaotic mix of black, white, and a small tint of red, all blending into a unified, white ashen color. He opened his eyes, and a cool, unwavering calm settled over his mind.