FWIW, would love to play proper shamans in this game. A number of my homebrew settings in D&D and elsewhere have a Spirit World. 4e made the Spirits a power comparable to the gods and the primordials and an actual part of the presumed setting.
I also love the Goetic in Invisible Sun that is all about making pacts and bargains with intermediary powers (angels, demons, spirits). It’s far more active than the D&D warlock. It’s the John Constantine sort of warlock and not the eldritch blaster warlock of D&D.