Associated Domain: Destruction.
Rage (Su): At 8th level, you can enter a fearsome rage, like a barbarian, for a number of rounds per day equal to your cleric level. At 12th and 16th level, you can select one rage power. You cannot select any rage power that possesses a level requirement, but otherwise your barbarian level is equal to 1/2 your cleric level. These rounds of rage stack with any rounds of rage you might have from levels of barbarian.
Advanced Player’s Guide. Copyright 2010, Paizo Publishing, LLC; Author: Jason Bulmahn.