That description instantly brings to mind Guts from 'Berserk'—though calling him just a 'dark knight' feels almost too mild for what he embodies. His struggle isn't just against physical foes but against fate itself, cursed with a brand that drags him into endless nightmares. The 'terminally ill' angle might not be literal, but the way his body breaks down from constant battle, yet he keeps swinging that massive sword, hits the same emotional notes.
What fascinates me is how Kentaro Miura crafted Guts' suffering into something weirdly beautiful. Every scar, every near-death fight, adds layers to his defiance. He's not a hero who triumphs; he's a force that refuses to stop, even when the world wants him to. That relentless drive makes him unforgettable, even in a sea of tragic antiheroes.