In the First Age, the Lightbringers Religion spread from its homeland in Dragon Pass across much of Genertela. These areas are where the Seven Lightbringers and their associates (Ernalda, Storm Bull, Mastakos, etc.) and friends (Humakt) are best known and recognized. In Prax, the Lightbringers entered in the first century of the First Age. In the later Second Age, many Praxians fled to the Wastes where Waha, Eiritha, and Storm Bull proved most useful. In most of these areas the Lightbringer deities have more or less the same names, although they often have local titles and variants. Nonetheless, an Orlanth worshiper from Sartar will be able recognize and participate in worship in Ralios or Fronela. Indeed, some of the most important historical developments of these cults occurred outside of the core homeland and were only later embraced in Dragon Pass (e.g. Orlanth Rex).
So what kind of early religions did the Lightbringers cult(s) displace? Whatever got the handful of survivors through the Great Darkness. Few of those spirits or minor gods provided much that was useful with the Dawn. The Theyalans brought social organisation, communication with outsiders, written records, agriculture and pastoralism, healing, and more. It is no wonder that the religion spread quickly across the Dawn Age landscape.
Would a Praxian Lodrili Man-and-a-half recognise and be able to participate in the ritual ceremonies practiced by the Lunar Lodrili in the Grantlands?
Yes, if they ever got to that point. But the Men-and-a-Half and the Pelorian Lodrilli first would have to engage in sufficient communication and trust to share magical secrets and then recognize the commonalities.The Dawn Lightbringers had people who specialized in doing just that, and had great experience in recognising shared symbols and communicating that with them. The Theyalan Missionaries were probably the most skilled and successful missionaries in Gloranthan history (more than even the God Learners or the Lunars).
So the Theylan missionaries were the hunting and waltzing bands? that’s the EWF version of the same.
The Theyalan missionaries are why sixteen centuries after the Dawn, you can call on “Orlanth” by more or less the same name from Junora to the Elder Wilds.
You can imagine how important Issaries was in all of this. And of course Issaries continued his speaking and trade missions across the world with the Middle Sea Empire.
Does this means that the knowledge of pre-Dawn magical geography in places converted to the Lighbringers was lost or deformed in some way? Not really. Most mortals survived the Greater Darkness by holding onto a very few tricks or being aided by a helpful spirit or god (Yelmalio shows up a lot there). The Lightbringers didn’t contradict that experience, but showed people how they were part of a bigger whole (think I Fought, We Won). Your truth remains true, but it is now part of a much bigger story. And this process continued into the Broken Council and the Gbaji Wars.
Is the Lightbringers Religion something people worship, like the Seven Mothers? A collection of gods worshiped as a unit, rather than individually? Lightbringers Religion is that whole pantheon of gods and goddesses around Orlanth, his associates, and friends.