Sins RPG Core Rulebook - Rules of Play says:
At its heart, SINS is a narrative role-playing game, specifically focused on telling the stories of powerful entities known as Nemissaries - reborn individuals back from the dead with a wealth of mysterious powers, who have risen once more to fight an eldritch hive-mind of the undying, known as the Brood, in the post-apocalyptic ruins of a 22nd Century Earth.
For all its high-octane combat and supernatural forces, SINS is a cinematic game about choice, morality and the consequences which come from wielding great and terrible power in a world desperate for heroes and leaders. It’s also about embarking on life-changing adventures, battling supernatural horrors, and often, simply surviving life in an unforgiving world fraught with danger, where even the Nemissaries’ great powers won’t necessarily protect them.