Off top, I think Piers Anthony’s Incarnations of Immortality is absolutely perfect for this, even the horrendous money grab that was book 8. Each book could easily occupy a complete season. I’m thinking 8-10 eps each, depending on the book.

Here’s a general synopsis from Wikipedia:

“The first seven books each focus on one of seven
supernatural "offices" (Death, Time, Fate, War, Nature, Evil, and Good) in a fictional reality and history parallel to ours, with the exception that society has advanced both magic and modern technology. The series covers the adventures and struggles of a group of humans called "Incarnations", who hold these supernatural positions for a certain time.”

It’s basically a struggle for the souls of mankind between Good and Evil and the 5 major “Earthly” Incarnations caught between the two. The series deals heavily in basic constructs of Judeo-Christian mythology, though it also touches on Hinduism as well. The series implies that all faiths and their respective deities are valid, though that aspect is only touched upon slightly and could be greatly expanded upon with a series. There's a fair amount of sex, manipulation, and chicanery involved that would translate very well to a post-GOT series, though they could easily trim the sex without a problem.