Yona emerged from Adolla alongside entities like Bugs roughly 250 years ago during the failed first Great Cataclysm. Arriving in the human world, he discovered an unconscious girl (Amaterasu) and encountered Raffles I, leader of an Adolla-touched caravan. Yona murdered Raffles and assumed his identity, transporting the girl in a container destined to power future settlements. Acting on the Evangelist's orders, he exploited Raffles' influence to establish the Holy Sol Temple. This religion manipulated humanity's collective unconscious, steering them toward Adolla to enable a second Great Cataclysm. As Raffles I, Yona founded Amaterasu with Haijima Industries, presenting it as a sacred energy source while concealing its true purpose within the Evangelist's scheme. Historical records, including Raffles' wife's diary, noted his sudden personality and behavioral shift after returning alone from the caravan journey, hinting at the impersonation. This deception became the enduring foundation of the Tokyo Empire's religious and social order. Approximately 12 years before the main events, Yona monitored Shinra Kusakabe, spreading rumors about his family's murder to prevent Shinra becoming a symbol of hope, thereby maintaining societal despair aligned with the Evangelist's objectives. Yona operates as a key member of the White-Clad's Knights of the Ashen Flame, specifically within their Commando Unit. His focus lies on manipulation and subterfuge over direct combat. A Third Generation pyrokinetic, he generates heat from his palms to control blood flow in facial tissues, enabling him to reshape appearances or induce fatal explosions by overheating blood. His physiology permits extensive shapeshifting, allowing him to alter his own form completely or absorb others into his body to dispose of remains or assume their identities. This power facilitated operations like the Asakusa infiltration, where he created doppelgängers of Company 8's Akitaru Ōbi and Takehisa Hinawa, and Company 7's Hikage, to incite conflict between fire brigades and delay evacuations. He typically relied on ambushes and retreated when opponents gained the upper hand, reflecting his cautious nature. Yona exhibits extreme loyalty to the Evangelist, viewing humanity's subjugation and the resulting chaos as artistic expressions. He perceives death not as tragic but as a transcendent return to the Evangelist, even expressing jealousy when allies like Haran perished. His speech includes invented portmanteau words like "scarious" (scary/delirious) and "wondiferous" (wonderful/terrific), highlighting his eccentricity. Despite grand ambitions, he displays paranoia and cowardice, avoiding direct confrontation unless victory is assured. During the Netherworld arc, Yona and Mirage separated Company 8 members, attempting to assassinate an exhausted Hinawa after Arrow's defeat. Arthur Boyle's arrival forced Yona's retreat. He later observed Shinra and Sho's battle alongside Haumea but could not track their Fourth Generation speeds. As the Great Cataclysm approached, Yona's form grew increasingly inhuman, with elongated limbs and distorted features. He oversaw the White-Clad's final preparations, announcing the completion of the Stone Pillars and remaining in the human world as Sumire transferred command to him until the Day of Ruin. In the climax, he witnessed the dark flames engulfing the world alongside Ritsu, smiling at humanity's extinction and anticipating his return to Adolla. Yona disintegrated during the Great Cataclysm's culmination, his form consumed by the inferno as the second sun formed.