Helios is the priest and guardian of Elysion, a sacred realm beneath Earth that once held the Golden Kingdom during the Silver Millennium. Elysion's existence is tied to Earth's protection, drawing power from human dreams. His core duty involves safeguarding the Golden Crystal, an object embodying Earth's dreams that weakens with unfulfilled dreams and strengthens when dreams are realized. This crystal manifests as a golden horn when he takes the form of Pegasus. In the anime continuity, including the *Eternal* films, Helios confronts invasion by Queen Nehelenia and the Dead Moon Circus, who seek the Golden Crystal. To protect it, his spirit escapes his captured body, transforming into the winged unicorn Pegasus. He finds sanctuary within the pure dreams of Chibiusa. Initially wary, he gradually trusts her, revealing his identity and mission. He grants Usagi and Chibiusa items like the Moon Kaleido Scope and Crystal Carillon, enabling them to summon his power for attacks like Moon Gorgeous Meditation against their enemies. The Golden Crystal remains central, symbolizing hope and empowering the Sailor Guardians directly. The manga presents distinctions: Nehelenia curses Helios into the body of his favorite horse, Pegasus, physically imprisoning him in Elysion while his spirit projects the equine form. Here, he does not guard the Golden Crystal; it resides within Mamoru Chiba as Earth's prince. His quest focuses on finding a prophesied maiden to break the crystal's seal, later revealed as Chibiusa's future self, Princess Lady Serenity. Their bond deepens through shared trials, with strong implications of a future romantic union where Helios becomes Chibiusa's prince. Whether in animation or ink, Helios forges a profound connection with Chibiusa. In the anime, their relationship evolves from secrecy to mutual reliance, culminating in her reviving him with her Pink Moon Crystal after Nehelenia's defeat. His farewell includes a kiss on her hand, symbolizing enduring affection and a promise of reunion. Physically, Pegasus appears as a white alicorn with orange eyes and a red teardrop jewel on his forehead, while Helios's human form resembles a boy around 12–13 years old, dressed in priestly garments. Post-conflict, Helios resumes guardianship of Elysion, maintaining a spiritual link to Chibiusa and hinting at future encounters tied to her destiny.