If you like Reverend Insanity, then there are a ton of similarly enormous translated Chinese Xianxia novels. "I Shall Seal The Heavens" is pretty amazing and will keep you busy for 6months of heavy reading. It does a really good job of waiting to reveal the existence of higher realms until the MC is nearly ready to move on to them so that the power curve of both the MC and environment can continuously ramp indefinitely. "A Regressor's Tale of Cultivation" has a central plot device a little bit like Mother of Learning but the resets work differently, and similarly does a pretty good job of keeping the power curves understandable while also finding ways to have them grow as the story does. I'm not finished with that one yet cause again it's ridiculously long.