The transaction with the church was part of the plan.
Of course, it's not that Mohe has any particular interest to gain from it, rather it's a deal that can barely be considered mutually beneficial.
Simply put, the church provides Mohe with materials for the Alchemist Association to remake bodies, while correspondingly, Mohe and the "Demon King forces" release souls they have "captured" according to the church's "wishes," fulfilling the church's "benevolent reputation." In this process, Doro needs to play the villain.
He acts as if he has some other use for collecting souls, prompting the church to bring out materials to redeem them. Of course, there might be some profit to gain from this, but how to negotiate isn't Mohe's concern. Even she feels a little tired.
After all, this body is still just a teenage girl, although she has already retrieved three body parts—the Celestial Scale is not something easy to wield.
She was utterly exhausted.