Premise is interesting but it sidetracks into rather boring gore. On top of it ~50% of novel are monologues. There are also 3 points which make it rather stiff:

Brainwashing is sort of answer to everything. It just looks like no one can be persuaded, bribed, blackmailed into anything cause they are brainwashed. Thanks to this sub characters are soulless. They don't grow, you don't learn their story or reasons. They just have different fetishes and looks.

Almost all main characters are OP. It doesn't look like even a full army can... more>> stop even one of them. As a result nothing really stops heretics from picking and killing each executive one by one but they are for some reason avoiding this. First city they attack has one executive, and they for some reason decide to wait until he leaves instead of quickly ganging him with 4-5 executives they have available

Another point is that author barely mentions how cult was born. Or how they got all their technologies. As I understood idea is that more believers grant more strength. But in this case church should be overwhelmingly stronger which is not the case. They are also using s*avery as a way to earn money but keeping in mind their behavior I highly doubt anyone would work with them <<less