Isaac, titled Black Sword Isaac, commands the Black Sword Knights as guild master within the Round Table Alliance. Before the Catastrophe, he lived as Araki Takafumi, a carpenter who co-established a construction firm in Kahoku. In *Elder Tale*, his Human Guardian-Gladiator class mirrors his battlefield persona—a tactician favoring relentless aggression and calculated maneuvers.

Initially abrasive and exclusionary, Isaac enforced elitist recruitment standards, clashing with figures like Woodstock W. He dismissed People of the Earth as mere NPCs and endorsed Hamelin’s exploitative EXP Pot schemes. Joining the Round Table Alliance catalyzed his evolution, unveiling a layered leader whose prior hostility masked efforts to unify his guild through disciplined combat training, diverting them from post-Catastrophe anxieties.

As Akiba’s governance took shape, Isaac contributed to security operations during the Libra Festival and allied with strategists like Shiroe and Krusty. Though inept at bureaucracy, he relied on Rezarick for logistics, enduring the subordinate’s jests. His mentorship of Iselus, Duke Cowen’s son, marked a turning point: safeguarding the boy from Westlande assassins forged his identity as a protector, deepening his sense of duty.

Relocating the Black Sword Knights to Maihama, Isaac trained the Glass Greaves knights under Cowen obligations. Once indifferent to politics, he backed Eastal in the Akiba election, opposing Eins’s radical policies and championing Raynesia’s bid. This pivot to pragmatic statesmanship earned him a New Round Table Council seat, where he balanced alliances and mediated disputes, prioritizing stability over ideology.

Isaac’s rivalries with Krusty and Shiroe spark strategic debates, though he frames these exchanges as professional duty rather than friendship. His trajectory—from a brash warrior fixated on combat to a coalition-building leader—epitomizes adaptation in a fractured world, where survival demands both sword and diplomacy.