The large island at the northwest end of Argonnessen is Seren, home of the barbarian tribes that beart the same name. Claiming descent from humans gathered from around the world to serve as the guardians of Argonnessen, the Seren barbarians are a wild and fierce people. Some thirty tribes, each paying allegiance to a different dragon founder, make their homes on the island, the two smaller islands nearby, and the jungle on the coast of Argonnessen. The coast itself is called Totem Beach, and it is considered neutral ground by the Seren tribes, which often war with each other. At Totem Beach they set aside their differences to give their worship to the dragons.

All the Seren tribes have a similar social structure. The warlord is the mightiest warrior, but this position is based purely on skill, and any member of the tribe can challenge a weak warlord. The warlord oversees all military actions, such as patrolling the land, organizing raids, and training young soldiers. Spiritual and domestic matters are overseen by a council of dragonspeakers—mystics who use wisdom and magic to guide the tribe. Dragonspeaker is a lifelong post, and authority within the council is based on age. Despite the warlike nature of the Serens, dragonspeakers hold the final authority and can overrule the decisions of a warlord, or even force a warlord to step down.

The tribes described below are a representative sample of the variety found among the Seren barbarians.

The Bringers of Fire were founded by a chaotic evil red dragon. One of the largest and most dangerous tribes, the Bringers have been known to completely exterminate Seren clans they view as unworthy. The Bringers of Fire paint their skin red before battle and make use of fl aming oil, and they have volatile temperaments.

The White Wanderers were founded by a neutral white dragon. It is a nomadic tribe that has been charged with protecting a series of shrines. The Wanderers believe in the power of knowledge and magic, and they have a high percentage of literacy and dragonspeakers among them. As such, many explorers find this the safest tribe to approach. White Wanderers have a cold, chilly demeanor, and never let their emotions show.

The Stormwalkers were founded by a lawful evil blue dragon. One of the smallest tribes, it is nonetheless deadly in combat and therefore highly respected. The Stormwalkers have developed a monastic tradition that emulates the natural attacks of the dragon.

The Frostblades were founded by a lawful good white dragon. While they ruthlessly defend the land from interlopers, they seek to preserve the weaker tribes from the more violent clans, such as the Bringers of Fire. The Frostblade dragonspeakers have learned the secret of alchemist’s frost and use it as a weapon in battle.

The Totem Guardians are not a tribe, but an alliance of elite soldiers drawn from many tribes. These warriors defend Totem Beach and the Great Barrier of Argonnessen. Typically, a dragonspeaker priest receives a dream-vision ordering her to send a particular warrior to Totem Beach to join the order, but in a few cases dragons have personally visited a tribe to call a Seren to the guardians.

Keith

Source: February 2023 Questions Thread

Per canon material (http://rpg.nobl.ca/archive.php?x=dnd/ebds/20040913a) the Serens don't have significant ongoing contact with dragons from either the mainland or the ocean floor. Seren isn't supposed to be Io'lokar; it's not an attempt to elevate humanoids. Not only have the dragons not unified the Serens, they've actively allowed them to fight one another. 

What is known of Seren is that its people have been taken from different cultures and ancestries and dropped in Seren; it's a little like a cross between Riverworld and Lord of the Flies. Each Seren tribe has a draconic founder and is encouraged to follow their example. On consideration, I can actually imagine that Seren is kind of like a PROFESSIONAL SPORTS LEAGUE for the Thousand, with each of the clans being supported by a particular flight in the Thousand; they don't directly interfere, but they watch the feuds between the Serens and give tips to their dragonspeakers, taking pride in the victories on their sponsored tribe. Meanwhile, the Serens themselves have no idea that they are essentially entertainment programming. 

But again; aside from the visions of the Dragonspeakers and occasionaly visits from a representative of their founder, the Serens don't have a lot of regular contact with dragons.