Battle of Divine Will is a conflict between civilizations able to use Magic promoted by God which happens once every 400 years. Each participant is fighting for the Legacy Shard, or Divine Will, of the other civilizations to upgrade their race through the absorption of their knowledge and characteristics and eventually become closer in power to God.
This conflict can't be easily resolved peacefully because when a race loses its Legacy Shard, the doomsday of the whole race will begin. Valkries also gives credit to this statement when she tells Roland of the sweetness of the legacy the Demon race received when they upgraded, a sensation so delightful that after one experienced it, it would forever be craved. 
According to Lan, God's apostle Traitor, the Battle of Divine Will is cyclic, the end of one will initiate the beginning of another. That fact is corroborated by The Guardian, which reflects that even though this Battle of Divine Will might end with a victor, it only meant the begining of another million year cycle, each with its own guardian.  Also, apparently, the Battle of Divine Will had gone through multiple of these cycles and no one knew how many races had been destroyed due to it. 
The current cycle had 4 races:
The Underground Civilization lost its Legacy Shard against the Deep Sea Demons and the Demons a hundred years after the end of the first Battle of Divine Will. With the upgrade of their races, the end of the Underground Civilization came with all of the surviving 'earthworms' wilting away and dying.
|The Battle of Divine Will is actually a battle devised by the Custodian to speed evolution up via competition between sentient species. Its origin is intertwined with Project Gateway and The Cradle. It officially ended when Roland became the new Custodian and the previous one left The Cradle. |
- Chapter 1317
- Chapter 1366
- Chapter 1372
- Chapter 1492-1493