Draigo is Sisyphus.
His fluff in the book is worded poorly, but he's stuck in the Warp fighting daemons for eternity because it amuses the Chaos Gods to let him think he's striking a blow for humanity by burning down Nurgle's garden and smashing Tzeentch's crystal labyrinth to dust, only to watch it become whole again with but a moment's thought from the Gods.
His fluff in the book is worded poorly, but he's stuck in the Warp fighting daemons for eternity because it amuses the Chaos Gods to let him think he's striking a blow for humanity by burning down Nurgle's garden and smashing Tzeentch's crystal labyrinth to dust, only to watch it become whole again with but a moment's thought from the Gods.