Temple of Syan is a story about the Divine Strength of Light and Free Will that each of us has.
One of the twelve 'Gods' - Syan, has fallen. He was imprisoned for wanting the knowledge about the creation would come to daylight.
When Syan falling came through the Stargate, the inter-dimensional flow was stopped, making it impossible for souls to get to the next level, because it was the Twelve Gods that served to protect its proper flow.
He decided that he would activate the gates again to bring justice in his revenge, for that purpose he needed eleven guards.