Mage/Priest Wars
From The Heretic Knowledge Vault
Specific details are unknown, except that the Mage/Priest wars were fought between Tsuiraku and Veracia. They began when Shrio Hideaki, a mage from Tsuiraku, attacked and attempted to siphon the power from Luminosita, the Veracian god-construct. The whole process, aimed at ressurecting Shiro's dead wife, ended in his death.
Mentioned here.