You know, the idea of Hashira becoming demons is such a wild twist that it makes me pause. The series 'Demon Slayer' establishes early on that the Hashira are the absolute pinnacle of human strength and dedication—they’ve honed their skills to fight demons, not join them. But if we dig into the lore, Muzan’s blood is the only way to turn someone into a demon, and he’d have to choose them personally. Given how fiercely the Hashira oppose him, it feels almost impossible. Still, imagine the chaos if one did flip sides—their Breathing Techniques combined with demon abilities? Terrifying!
That said, the narrative weight behind the Hashira’s purity of purpose is huge. Their resolve is what keeps them from even considering it. Characters like Shinobu, who lost her sister to demons, or Giyuu, who carries so much guilt, would never entertain the idea. The series leans hard into themes of humanity versus monstrosity, and the Hashira embody that struggle. A demonized Hashira would undermine everything they stand for—though as a 'what if' scenario, it’s a fun thought experiment.