In between the Malkioni lands and the Lunar Empire are two regions the “Lightbringers Belt” and the “Old Gods”.
Now the Lightbringers Belt we all know – this is the area of Orlanth and the Lightbringers, spread in the First and Seond Ages past Peloria to Ralios and Fronela. Even in the late Third Age the Lightbringers cults predominate in these areas (at least among humans – they are certainly known to the Elder Races here as well).
The Old Gods are interesting – these are areas that in the First Age were predominantly a combination of Hsunchen and other Beast cults, spirit cults and shamanism. Pendali, Telmori, Galanini, Tawari, etc. They got exposed to both the Lightbringers and Malkioni, and sampled both like an à la carte buffet. Along the Janube River, we have the Arrolian Territories, as well as the Sky-worshippers. In Safelster, we have Stygian heresies, Ehilm worship, city gods, and grain goddesses, as well as Lightbringers and orthodox Malkioni.
Those “Old Gods” areas are going to be some of the more heterogenous areas in Genertela. Every city might have a different ruling cult, or even no ruling cult at all.
So let’s pick a few –
On the banks of Lake Felster, the large city of Estali has as its main cult the Great Green Lady (Ernalda), and also has a great library of Lhankor Mhy, the largest in Ralios. However, the ruler of the city is whoever can wield the Purple Sceptre of Serpent Sentience, which is thought to date back to the Second Age and the Empire of the Wyrms Friends.
Just 25 km away is the allied client-city of Gamol, home to a shamanic tradition of the Ancient Beasts Society. The shamans are usually women and they still worship the Old Gods.
About 35 km away from Estali is another allied-client city, that of Tolin, where Ehilm is worshiped as the Sun God. Each Sacred Time, the city stages a wild and drunken festival intended to revive the god in the Underworld.
Now of course there are also plenty of other cults in each city – I am sure there are minor temples or shrines to Chalana Arroy, Issaries, Orlanth, Humakt, and the Invisible God, as well as to the god of the city and so on. But little unifies the cities here.