TV-Series
Description
Ruijerd Superdia (or Speldia) hails from the Superd tribe, a warrior race native to the Demon Continent. He rose to lead the Superd warrior group under the demon king Laplace at an exceptionally young age, recognized for his formidable combat skill. His past includes marriage to Luwelia and fathering a son, Luiweld. This life shattered when Laplace betrayed the Superd, providing them with cursed, pitch-black Devil's Spears that induced a berserk frenzy. Consumed by this madness, Ruijerd mortally wounded his own son; Luiweld's final act shattered the spear, freeing Ruijerd from the curse. Overcome by guilt, Ruijerd rejected suicide and vowed vengeance against Laplace. Years later, he intervened decisively in the battle between Laplace and the three heroes, striking a critical blow that contributed to the demon king's defeat.

Physically, Ruijerd possesses porcelain-white skin, emerald-green hair, and a distinctive red gemstone – the Third Eye – on his forehead. A prominent scar runs from his right forehead down across his face to his left jawline. He typically wears a tribal vest exposing his torso and arms. Following his meeting with Rudeus Greyrat and facing widespread prejudice against his race, Ruijerd adopts a disguise: he shaves his head and wears a headband to conceal the Third Eye. He also wears a necklace gifted by Rudeus, originally belonging to Roxy Migurdia.

Ruijerd adheres to a strict warrior code emphasizing the protection of children and unwavering loyalty to his promises. He reacts with fierce violence to threats against children, demonstrated when he became enraged after a child's death during a monster encounter and murdered captors imprisoning children. Though fundamentally kind-hearted, his rigid moral principles lead him to punish minor offenses harshly, sometimes causing misunderstandings. His initial hostility toward humans softens through his bond with Rudeus, though he remains stoic in social interactions.

His journey intertwines with Rudeus and Eris after the Teleport Incident, rescuing them on the Demon Continent. Together, they form the adventuring party Dead End, aiming to return to the Central Continent while working to restore the Superd's reputation. During this period, Ruijerd uses the alias "Watch Dog." He assists in critical missions, including rescuing the family of soldiers held by Pax Shirone and confronting the Dragon God Orsted on the Red Wyrm Mountains, a battle they lost but survived. He later encounters Norn Greyrat, protecting her from harassers and offering counsel that aids her reconciliation with her family. Reflecting on his own parental failures, he volunteers to escort Norn and Aisha to Rudeus in Sharia, fulfilling this duty before resuming his search for surviving Superds.

Years later, Ruijerd locates a Superd settlement afflicted by an incurable plague within the Forest of No Return in the Biheiril Kingdom. He reveals the illness, Drain Syndrome, is only temporarily suppressed by the Abyssal King Vita, who possesses him—a fact he concealed from the village elders. Removing his headband exposes a blue jewel with ominous markings, confirming this possession. Despite this, he refuses Rudeus's request to join the battle against Laplace, prioritizing his tribe's immediate survival. While the plague's treatment is later facilitated by Cliff Grimoire, Ruijerd's possession remains unresolved.

Ruijerd wields a unique Superd Spear formed from his own tail, hardened over centuries into a trident-like weapon that sharpens and strengthens with use. His combat mastery includes Sōjutsu (spear combat), honed over 400 years, enabling him to fell high-ranking monsters with single strikes and briefly contend with opponents like Sword God Gal Farion. His Third Eye functions as a mana-detecting radar, granting situational awareness beyond line of sight. Additional abilities encompass superhuman strength exceeding Ghislaine Dedoldia's, advanced stealth techniques, and the extended lifespan characteristic of demonkind.