The Prime Soul of King Sisyphus, former tyrant of Hell's Greed layer. Sisyphus rallied his fellow sinners in an insurrection to overthrow the forces of Heaven that subjected them to endless punishment, but was killed, his body entombed inside one of Greed's giant pyramids. His soul was trapped in the Flesh Panopticon, located deep within the city of Dis, on the Heresy layer of Hell.
Even if the battle is futile, Sisyphus takes joy in the act of struggle itself, and doesn't regret a second of it.