Erald Grimwald holds the title of archduke in the Sorcerous Dynasty of Sarion, wielding considerable political power. He is uncle to Emperor Elmesia El Ru Sarion and father to Elyun Grimwald. Despite his familial relationship, Erald is notably younger than the Emperor. His mother, Ellis Grimwald, leads Sarion's thirteen royal families. Erald's brother, Sarion Grimwald, perished in battle against the Chaos Dragon prior to both the kingdom's founding and Erald's birth. His appearance features blonde hair styled to frame his face and distinctive green eyes that visibly widen during moments of intense emotion. Erald typically adorns himself in expensive, aristocratic attire befitting his station. For travel, he often employs a homunculus body, demonstrating his magical proficiency. Erald presents a generally calm and competent demeanor in diplomacy and politics. However, fierce protectiveness toward his daughter Elyun surfaces readily, sometimes driving him to irrational actions if he perceives her threatened. This overbearing nature is well-known among associates, including Elyun's adventuring party, who disapprove. His deep love for her consistently prioritizes her safety above all else. During the Octagram Soars Arc, Erald journeyed to the Jura-Tempest Federation intending to attack its leader, Rimuru Tempest, over a misunderstanding involving Elyun. Elyun intervened, explained the truth, and averted conflict. Subsequently, Erald allied with Rimuru and collaborated with Gazel Dwargo, King of Dwargon, to propagate a specific deception: that the Storm Dragon Veldora defeated the Falmuth army, with Rimuru credited for pacifying Veldora. This false narrative aimed to stabilize regional perceptions. In the Territory Seizure Arc, Emperor Elmesia tasked Erald with negotiating a peace agreement with Tempest. Though harboring concerns about allying with a monster nation, he followed orders. Elmesia overwhelmed him with information detailing Tempest's plans and connections, including those involving the merchant Yoshida. Erald attended the festival opening Rimuru City in the Monster City Arc. He observed the martial arts tournament and participated in financial discussions alongside Rimuru, Gazel, and Elmesia. When Elyun entered the Dungeon event, his anxiety escalated dramatically, requiring repeated calming interventions from Elmesia. His relationships extend beyond family. He maintains cordial ties with residents of Rimuru City and navigates complex dynamics within Sarion's leadership. His alliance with Gazel underscores political pragmatism, while his interactions reveal a blend of aristocratic authority and personal vulnerability, particularly concerning his daughter.