Perhaps I should rephrase. It took me a really long time to get decent at this game. I think I am pretty alright now. Still no O3 completes yet, but that will change soon!
The fact that you have 5 8/8s without doing any halls is pretty nuts, honestly. Very impressive. If you are opposed to the massive discord steamroll trains (which I think is the correct opinion to have) and still want to experience a cult run, I suggest checking out Malice. They only have a run every couple hours, and it is almost always <20 people, which makes for a pretty chill time. You generally still have a few knights which trivialize the boss fight itself, but it is a good way to get introduced to the dungeon.
EDIT: I see you verified for Pubhalls. Also a good way to get introduced to the boss fights, particularly mbc and void. Cults in pubhalls are completely braindead, though, since you just walk to the troom and wait for the rushers to clear, then wait in the hideout until the rusher gets to boss, then smack the cultists while the knights stun them. Completely, completely braindead. Mbc and void are quite the experience for the first couple times! Much, much easier with player opacity options now, though.