Reinhard van Astrea is a human male knight approximately 20 years old, standing 184 cm tall with fiery crimson hair and blue eyes, distinctive traits of House Astrea. He is the current Sword Saint, inheriting the title at age five following his grandmother Theresia van Astrea's death – an event that fractured his family. His grandfather Wilhelm blamed him for Theresia's loss of the Divine Protection during her battle with the White Whale, while his father Heinkel descended into alcoholism and resentment. His mother Louanna has remained in a "Sleeping Beauty" comatose state since his early childhood. Serving in the Royal Guard of the Kingdom of Lugunica, Reinhard embodies chivalric ideals, acting with justice, fairness, and respect. He avoids unnecessary violence but displays decisive lethality when required, such as executing the imperial spy Miles. His immense power isolates him; the "Reinhard Law" enacted when he was eight prohibits him from leaving Lugunica, as his presence could be seen as an act of war. He internalizes his role as a "hero," adhering to societal expectations even at personal cost, accepting world-dictated decisions about his life. Reinhard possesses unparalleled combat capabilities. His base physical prowess and swordsmanship are exceptional, surpassing contemporaries like Cecilus Segmunt in raw power and Julius Juukulius in technique. He wields the Dragon Sword Reid, a holy blade capable of cutting through space and intangible entities like spirits. His abilities are augmented by numerous Divine Protections – boons granted by the world's core, Od Laguna – which include: - Auto-dodging all physical and magical attacks (Arrow Avoidance, First/Proceeding Attack Immunity). - Statistic amplification under specific conditions (rain, sunlight, night, morning, or bleeding). - Utility functions like walking on water or clouds, poison/illness immunity, and resurrection upon death ("Phoenix" protection). - Adaptive capabilities, such as spontaneously acquiring new Divine Protections like "Sunburn" to counter threats. His defective gate continuously absorbs ambient mana, nullifying surrounding magic and amplifying his physical traits. This absorption has no defined limit, theoretically allowing planetary-scale mana consumption. In *Isekai Quartet*, Reinhard appears as a student in Class 1. His interactions mirror his original series relationships: he views Subaru Natsuki as a reliable friend, collaborating during events like the cavalry battle stalemate and alliance against teachers. As Felt's knight, he remains devoted despite her frequent rebuffs, such as rejecting his Valentine's chocolate. He maintains camaraderie with fellow knight Julius Juukulius, though he regrets failing to prevent Julius' duel with Subaru. Notable combat feats include overpowering top-tier warriors like Cecilus with ease, emerging unscathed from a dragon's breath, and battling the mind-controlled Divine Dragon Volcanica in the Sand Sea, noting its weakened state under control compared to their prior encounter. His resilience is demonstrated by surviving being launched to the moon and returning to Earth.