Looking for a novel where the mc establishes an evil cult worshipping a god (can be mc or some other thing). Preferably not something like Warlock of the Magus World, where it only happens in a single arc and isn't really important to the story.
I thought NUF was that ... but seriously most of what I read that has that it seems it's only for an arc, except for https://www.novelupdates.com/series/skeleton-knight-in-another-world/
Evil God Average. The evil cult isn't really that evil though, they just worship the Evil God. Ignoring the time when they offered a little girl as a human sacrifice in a ritual full of depravity and lust. They are mostly there for comedy. Oh, and their Scripture is so dangerous to read that it is of the highest threat ranking. ... which the MC made and the Pope of their religion teaches the young kids how to write the Scripture over and over to make them literate.