Gros, a Xenos—a sentient monster born from the Dungeon—emerges as a pivotal force in the clash between humanity and awakened monsters. Leading a faction within his community, he initially champions hostility toward humans, shaped by centuries of cyclical violence and entrenched distrust. His conviction that coexistence is unattainable stems from humanity’s deep-seated animosity, further solidified by tragedies such as the capture, torture, and eventual death of Rayne, a fellow Xenos, at the hands of hostile human groups. After Rayne’s demise and the loss of other allies, Gros abandons alliances with the deities Fels and Ouranos, who had supported the Xenos, and rallies his followers to exact vengeance. He spearheads assaults on human territories, including the Dungeon’s 18th floor, intensifying hostilities. This aggressive strategy starkly opposes the diplomacy pursued by Lyd, a fellow Xenos leader, underscoring Gros’s unwavering commitment to retribution. Renowned for his formidable combat skills, Gros proves a relentless adversary in clashes with adventurers such as Bell Cranel. Yet his rigid worldview evolves during a decisive confrontation. In a self-sacrificial duel against Bell, he concedes the necessity of trust between Xenos and humans, prioritizing his species’ survival over vengeance. This shift reveals a nuanced transformation from his earlier absolutism. Though his encounters with Wiene, a young Wyvern Xenos shielded by Bell, subtly challenge his outlook, Gros’s actions remain anchored in securing autonomy for his kind. Post-conflict, the Xenos retreat into the Dungeon’s shadows, leaving Gros’s legacy as a symbol of both ideological rigidity and the fragile potential for understanding amid generations of bloodshed.