The Last Star of Tevyat

Centuries ago, the last Archon of Tevyat had mysteriously disappeared. Without her guidance, humanity independently continues to evolve until they reach it's peak, completely unaware of the impending doom they are heading due to the lack of divine powers. On the other hand, six orphan children had gathered and lived in the woods, living under the care and tutelage of a mysterious otherworldly young girl who lived in there.