Althea didn't know every reason behind that requirement. She had her suspicions but she only knew what she had witnessed directly. Arros had run through many candidates over the years. Many souls pulled from different planes, each bearing Error authority driven by faith, each transplanted into their world through the same process. But something had gone wrong with every single one of them.
Some died in the transmigration itself. There were factors in moving a soul across planes that even Arros, at the height of his power, couldn't fully account for.
Some survived the crossing but became so absorbed into their new life and new identity that whatever divine authority they had carried never developed at all. They lived their lives as Ossuarists and died fully assimilated into their new world, never remembering anything of who they truly were or where they were truly from.
