"Halo! It's divine wind will rush through the stars, propelling all who are worthy upon the path to salvation!"
The High Prophet of Mercy was one of the three Prophet Hierarchs that led the Covenant High Council during the Human-Covenant war. He was originally a Philigost and a Councilor, but soon was promoted to a Hierarch. He, alongside Prophet of Truth, made Thel Vadamee an Arbiter and tasked him with eliminating the Heretics. After killing Sesa Refumee and his followers, Thel was sent by Truth and Mercy to retrieve the Index. Tartarus followed Arbiter and took the Index, Mercy and Truth then began the Great Schism: a Covenant Civil War. Mercy and Truth alongside Tartarus, some prisoners and Brute Honor Guards went to the Phantoms on High Charity and planned on escaping, but Mercy was attacked by a Flood Infection form and abandoned as Truth ordered. Mercy started dying on High Charity and John 117 encountered the prophet. John asked Mercy where Truth is heading to, so Mercy told him. John violently grabbed the flood from his neck, instantly killing Mercy but saving him from becoming one of the flood.
- "Why was it not destroyed with the rest of their fleet?"
- "There will be order in the council!"
- "The Taming of the Hunters, the Grunt Rebellion-were if it not for the Arbiters, the Covenant would have broken long ago!"
- "Their slander offends all who walk the path!"
- "The tasks you must undertake as the Arbiter are perlious, suicidal! You will die, as every Arbiter has before you! The council will have their corpse."
- "Even as the Humans' annihilation filled us with satisfaction, the loss of one of the Sacred Rings wracked our hearts with grief."
- "Halo! Its divine wind will rush through the stars, propelling all who are worthy along the path to salvation."
- "Salvation for us all!"
- "Earth...to finish what we started. And this time, none of you will be left behind..."