Bound beneath Adar, Ran Iishiv is a force of chaos and destruction. Some believe that Ran Iishiv reflects Khyber’s primal hatred of creation itself, the burning desire to tear down the Material Plane and start anew. Whatever the truth, Ran Iishiv was exceptionally powerful and feared even by other overlords; it’s believed that the wild zones to Kythri in Adar are the result of Ran Iishiv literally tearing through reality. Even while bound, the Unmaker’s fury is a powerful force. Ran Iishiv may be the source of the storms that batter Adar, and some accounts claim its rage created the volcano of Korrandar.
Ran Iishiv has no allies among the Lords of Dust; it’s possible fiends tied to other overlords would help prevent its release. Ran’s primary servants are the Endseekers, cultists who have heard the Unmaker’s dreaming whispers and seek to return reality to primordial chaos.
Source: Chronicles of Eberron