To be One

12 boys from different regions were collected by an old monk because they were neglected by their surrounding. They were called as monster back at their region it is all because they were born with superpower. An old monk name Nung Gu travelled across sea and mountains to get to each regions to find all 12 of them. After he found all the neglected 12 boys,he brought them to his home. He trained them. He taught them how to control their powers. 10 years later, the boys reached their 20. Nung Gu brought all the boys to a secret room underground. The boys amazed with the view of the room. Nung Gu took out a scroll from the old dusty bookshelf near the closet.
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What's with the scroll?