From Halopedia, the Halo wiki
During the circulation and course of the Great Schism, he was with Imperial Admiral Xytan 'Jar Wattinree aboard the spearhead flagship, Sublime Transcendence. Though bent with old age, he retained a better sect of intelligence and worked as a religious and intelligence gathering consultant on the Imperial Admiral's behalf. It was he who discovered that the renegade ship Bloodied Spirit was headed to Onyx.
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