Torga

This must be the Stone of the Burning Heart. Don't regard it as any ordinary stone. The stone monsters you met were just the ancient souls that were nurtured by the earth after Genesis. It could be the recent eruption of Wraith activity that drives them to rise to the ground. According to the ancient documents, the Stone of the Burning Heart always appears with a mighty ancient creature. Go and seek this ancient being. If it's controlled by the Wraiths, be careful, as it may attack you.