I do love me some Dark Souls.

The bleakness of the setting would be upset a bit by the fact that there are others joining the fight, unless they are all equally damaged in some way.

An idea, this is the beginning of a new age of fire, and this is the story of how civilization grows again.  The remaining unkindled clear the way for actually peace to reign again.  That's their purpose, and when the world is safe for the peoples to thrive, they'll have no place in it, having lost their purpose.