I'd say it's Three Six that is the best comparison to Black Sabbath
Dark/satanic subject matter/Themes of horror like madness, murder, evil
Not mainstream friendly at first but quickly grew a cult fanbase
One star solo member goes on to have his own successful run (Ozzy and Juicy)
Or you could compare Ozzy's solo run to when 3 6 came up in the 2000s
Influential to this day, it's hard to find a band that didn't steal from Sabbath, just like it's hard to find a rapper who doesn't steal from 3 6 production
This might be a stretch but just like Iommi is considered the GOAT riff writer, I think DJ Paul and Juicy J were the some of GOAT beat makers
Innovative instrument work/innovative flow work
Had a sound that didn't necessarily catch on worldwide til a decade or so after they came out