This was the intersessionary email (slightly tweaked for context) for the Society of Light folks. It’s worth noting that the Order Luminous is directly stolen from the “Luminous Order” from the Shattered Gates of Slaughtergarde module, as are the Serene Guardians (a prestige class). The description of the Order is pretty much verbatim taken from the module.
Now Frater Nikolai was off dealing with the Caves of Chaos because he was tasked with it after getting a break on his training for 3rd level, and Brother Illya has merely been accompanying him. It is worth noting that while Castle Seraph is an outpost of the Society of Light, it’s a very small one. It isn’t exactly brimming with Lightbringers and Paladins, there are a grand total of five priests on hand. The Curate, Frater Lionel, and his three acolytes, the Brothers Hugh, Tomas, and Emile – plus a Cloistered Cleric by the name of Brother Simeon who acts a scribe for the castellan. This gentleman goes by the name of Sir Lucian Sc. Valour, Guardian of Seraph Keep, and he is the only paladin at the Keep. There is also a half-elf warrior/mage by the name of Raeburn who acts as an advisor to the Sir Lucian and seems to be highly trusted. There is also a wandering Warrior-Monk by the name of Master Birinaj, not of the Endorian Monastery to the south in Albion where Brother Illya hails from, but of the much smaller and reclusive Monastery Tel Hazor from deep in Shahuda Mountains to the north (also known as the Mountains of Witness or the Mountains of Martyrs). Commonly known as the “Serene Guardians”, these Warrior-Monks are quite friendly with another obscure group, the Order Luminous. Perhaps unsurprisingly, both Frater Lionel and Sir Lucian (as well as the officers of the Keep) are members of the Order Luminous, an obscure order that dates back to Wars of Binding and has always been located here in these mountains where they are concerned with incursions of the Dearth and the machinations of the Fallen.
The actions of Frater Nikolai impressed Frater Lionel and Sir Lucian to such a degree that they are offered membership in the Order Luminous. This is, by the way, not exactly something you can refuse without giving offense – it doesn’t conflict with membership in other Orders, nor does it particularly conflict with either of your other religious directives. It’s an Order basically on the lookout for evil, especially the sorts of hidden inequity that might lead to greater woe down the road. The Order Luminous was created to stop demonic invasion, so it is particularly concerned with anything that lets evil gain a foothold such as a secret demonic cult engaging in foul rites within a forest, or an evil lycanthrope hidden within a community. It strikes at any growing evil, uprooting it before it can bear bitter fruit.
The Order Luminous places great faith in the self-reliance of its members. Once accepted within its ranks, the Order is confident that you take its mission to heart. Thus, the order demands few specific duties from you beyond those expected of other members of the Knights-Militant of the Society of Light. If evil shows its face, then the Order Luminous asks that its members to vanquish it. But the Orders leaders rarely demand that a specific agent undertake a specific mission. While its members are always welcome in the shining citadels of the Order, it is common for Luminaries to be away from order for months at a time, even if they aren’t on any specific quest or mission. Joining the Order advances one’s career as a hero, it doesn’t constrain it.
It is made perfectly clear to Gregor that once he takes his next initiation as a paladin (at 3rd level) he will be welcome to take a place in the Order Luminous as well.
Brother Illya continues to study with Master Birinaj, and the two spend a great deal of time discussing philosophy as well as honing and practice the skills and abilities of the Warrior-Monk – such that Brother Illya is relatively certain that if he continues to study with Master Birinaj he might very well be able to understand the mysteries of the Serene Guardians who seem to be especially in tune with the harmony and resonance of what they call the Divine Song.
This is how you link modules together by the way. Find something from one that works with something from another and build a bridge. It isn’t rocket-science, it isn’t even very hard nor does it insist that the players ever do anything to follow-up on the things that would take them towards the next Slaughtergarde. Heck, I’m ignoring most of the “mini-campaign setting” for that module (which doesn’t fit my world much at all) and I can scatter the bits all over the Shahuda Mountains as i desire.