Voadam
Legend
Most of the direct Greyhawk material I have read does not mention a tie between faith and power at all.Does anyone know if Greyhawk deities work that way too? I sure as hell hope not.
Xagyg ascended by capturing demon lords and demigods in a big magical artefact trap and using their power to make himself a demigod.
From the 1e boxed set major gods are worshiped but rarely interact in mortal affairs for example and explicitly few hold them as patrons.