The Cell was created by the Sentinel to contain Nedel within a continent. It was made by Amber weaved by the Sentinel in order to be indestructible. The Cell operates as a pocket plane within another plane and cannot be accessed from the outside.
The Cell powerful energy that destroys or distorts any living organism within it. Not all species or organisms react the same way under its effect but the transformations cannot be reversed, even upon the Cell's cancellation.