Chapter 4: Breath of the Sun × First Use of Nen
That smile—warm, gentle—was both familiar and unfamiliar to Roy.
Back in the Zoldyck family, he had never once seen Silva smile.
For a cold-blooded killer, a smile seemed almost… unnatural.
Not even a twisted grin, not a cruel sneer—never had such an expression crossed his father's face.
Sometimes, Roy even wondered if Illumi's perpetually blank, puppet-like face was the result of Silva's influence.
After all, the elders in the family had repeated the same lesson countless times:
"An assassin must never let emotions cloud their judgment."
"Whether joy, anger, resentment, or grief, nothing must show on your face. Only absolute calm ensures the mission's success—and prevents you from exposing yourself to danger."
Perhaps it was because Silva and Zeno saw that Roy could never fully embody this creed that they judged his potential as an assassin to be limited.
And they weren't wrong.
Unlike them, Roy believed firmly that he was, first and foremost, a person—and only second, a professional killer. He refused to invert that order, to become a machine stripped of emotion, existing only to kill. That was also why he had always disliked Illumi.
Illumi was too formulaic. Too hollow.
The family's training had already robbed him of the joys of being a child—of running to his siblings, chattering away with his discoveries, sharing laughter and tears, tattling about petty quarrels.
Instead, Illumi had been reduced to a lifeless doll, endlessly cycling through joyless, mechanical training.
A flood of such thoughts flashed through Roy's mind—
—when suddenly, a tiny pair of arms latched onto his thigh.
Kamado Shigeru tilted his head back, eyes wide with anticipation. His soft, childish voice called out:
"Niisan~ candy~!"
Roy chuckled, quickly pulling a small cloth pouch from his chest and tossing him a piece.
And just like that, the room exploded into chaos.
Nezuko wanted one. Takeo wanted one. Soon Roy was besieged by little hands and eager voices, surrounded and overwhelmed.
He stroked Nezuko's head, patted Takeo's back, reminded Shigeru not to eat too fast lest he choke. In the flickering glow of the oil lamp, his figure shone gently in Tanjiro's eyes—finally restoring a sense of familiarity.
Yes. This was the Niisan Sumihiko he knew.
That fleeting specter in the forest? That had been something else entirely—something like a demon wearing his brother's skin.
"Niisan, me too…"
Tanjiro rubbed his cheeks, grinned, and joined the fray. At least he was sensible enough to first slip the basket from Roy's back, relieving him of the burden.
That small gesture lightened Roy's load far more than the boy could know.
Roy gave him a grateful nod. After handing out candies, he turned and walked toward Tanjuro.
"Is this… for me?"
Tanjuro looked down at the candy in Roy's outstretched hand, momentarily stunned. His throat tightened. He couldn't even remember the last time he'd eaten candy. The memory was so distant he could only vaguely recall it being back when his own father—Tanjiro's grandfather—was still alive.
And now, all these years later… his own child was offering him one.
His eyes misted.
Gently, he shook his head.
"Father doesn't like sweets. You eat it."
But Roy didn't withdraw his hand. His voice was firm.
"Father gets one. Grandma gets one. Mother gets one. Everyone gets one."
Seeing the boy's insistence, Tanjuro smiled at last. He unwrapped the candy and let it rest on his tongue, savoring it. Then he gestured for Roy to help him into the ceremonial robes.
It was time to perform the Fire God Dance—Hinokami Kagura.
A Kamado family tradition passed down through the generations: offering a dance to the Fire God, praying for peace.
To others, it was just ritual. But Roy knew better. The flowing robes, the mask emblazoned with the blazing kanji for "Flame," the earrings Tanjuro wore—decorated with the sun and mountains—they all pointed to the truth.
These were the relics of Yoriichi Tsugikuni.
The Breath of the Sun.
The origin of every breathing style: Moon, Rock, Wind, Water… all of them traced back to this.
Roy's heart pounded. This was it—his chance to reshape his body.
Tanjuro's expression shifted. Clad in red-and-white, he no longer seemed a frail man, but a vessel of fire. He beckoned.
"Come."
Roy could hardly suppress his excitement. He reached back and tugged Tanjiro forward.
"You too."
Before his little brother could even process the words, Roy stepped out into the courtyard beside their father. At that moment, he activated Gyo.
Unlike the advanced principles of Nen—Ten, Zetsu, Ren, Hatsu—Gyo was a simple application: focusing aura into the eyes.
Thanks to Gotoh's careful instruction, combined with the Zoldyck blood running through his veins, Roy had mastered it easily.
A milky-white sheen covered his eyes. He stared unblinking at Tanjuro's movements.
Through the flow of his aura, he recorded them, frame by frame, as though engraving an animation into his mind.
First form: Dance.
Second form: Clear Blue Sky.
Third form: Raging Sun.
Fourth form: Fake Rainbow.
Fifth form: Fire Wheel.
Sixth form: Burning Bones, Summer Sun.
Seventh form: Sunflower Thrust.
Tanjuro moved like a spirit of flame dancing amidst the falling snow. Roy followed at his side, imitating each motion with precision.
Beside them, Tanjiro struggled along, clumsy but determined.
One repetition. Two. Three.
By the fourth, Tanjiro's breath grew ragged. He bent over, gasping, sweat pouring down his face. Wide-eyed, he stared at his father and brother, confusion gnawing at him.
Why… why did his always-ailing father suddenly have such stamina tonight?
And why had his elder brother, who had started as clumsy as him, suddenly caught up—moving in perfect rhythm with their father?