Outside the Main City lies an incredibly vast sky, yet this sky no longer belongs to the human race...

Most humans hide within the Main City, not daring to venture out unless absolutely necessary, as many scattered demonic creatures roam outside, preying on those who dare to leave...

For humans to venture out, they must be protected by at least a Saint-level expert; otherwise, they are unlikely to return...

Sometimes, even when encountering powerful demonic creatures, Saint-level experts may meet their demise...