Demon Slayer: When the Rengoku Flame Burns Dark

What if the legendary Rengoku bloodline—guardians of the Flame Breathing technique for generations—produced not a hero, but a demon? When a prodigious doctor abandons healing to pursue martial power, the question isn't whether he'll reach the Upper Moons... it's what he'll destroy along the way. In this twisted alternate timeline, the flame that once protected humanity now threatens to consume it. Will this fallen blossom wither into nothingness, or will it take root in darkness and grow into something far more terrifying?