Ok then, the background for the rise of dragons in Khorvaire according to Tersival…
After centuries of searching Azaryanis, an ancient blue dragon sworn to the Talons of Tiamat, a Cult of the Dragon Below, followed hints of the draconic prophecy to a long buried cavern beneath the Demon Wastes once used by Tiamat when she roamed Eberron in the Age of Demons. Within the cavern were manifestations of the draconic prophecy and ancient, multi-hued dragon scales shed by the dragon queen herself.
Interpreting the Draconic Prophecy manifestations to mean the cavern site was a key to freeing Tiamat’s prison in Argonnessan, Azaryanis summoned dragons and loyal cultists to the Demon Wastes where they began building a temple above the cavern.
When she witnessed the mesmerising effect Tiamats’ scale had on some of the lesser dragons with her that caught sight of them, Azaryanis recognised power with the scales and had six masks forged from the scales that she enchanted and distributed among trusted cultists to aid them in influencing or commanding other dragons that she knew would oppose the cult.
Nagas and Yuan-ti inhabiting nearby Shaazarak, were awed by the cult’s dragons into service of the cult while barbarians from the Carrion Tribes and Plaguebearers inhabiting the wastes nearby were enlisted or enslaved to form the core of a growing army. As the cult consolidated a power base around the ancient temple, bands of barbarians, led Yuan-ti and sometimes Nagas began raiding nearby areas for loot and slaves that were in turn set to work rebuilding the dragon queen’s temple.
As raids expanded further afield, a hunting lodge in the mountains overlooking Festering Holt occupied by members of the Order of the Emerald Claw, was discovered and captured. Surviving order members revealed an ancient teleportation circle that was once part of a teleportation network built by the ancient Empire of Dhakaan, before the empire was destroyed by the Daelkyr. One of the last surviving remnants of the, the circle links the lodge to Castle Naerytar, an abandoned keep in the Eldeen Reaches near Merylsward.
The cultists were then joined by Glazhael, an allied white dragon who brought with him Skyreach Castle, a cloud giant forged flying fortress captured by the cult long ago in the Frostfell and a pair House Lyrandar airships, spotted exploring the area around Desolate were quickly captured in dragon led assaults. When another airship was later spotted searching for the first two, this was also captured and the surviving airship crews were forced into service as mobile raiding bases under the command of trusted cultist leaders.
Gaining confidence, the cult establishes a forward base at Castle Naerytar and begins raiding the Eldeen Reaches in search of more loot and slaves…
The PCs begin the campaign attending a trade fair in the Eldeen Reaches when the blue-dragon-led forces first attack and pursue raiders to rescue captured villagers. Tracking them into the Towering Wood they discover the raiders camped on an escarpment with a captured airship hovering nearby - a clever rescue liberates captives and the airship as well as providing clues about other raids among maps and papers left on the airship by the raiders' leaders.
When the clues imply attacks on other settlements they use the airship to try and take warning to Merylsward but find the area has already been ravaged by white-dragon-led raiders. The maps lead them to Castle Naerytar deep within the nearby forests (a long abandoned and forgotten effort to civilize the area before the Last War) and an investigation there leads to an encounter with a green dragon that had effectively been enslaved through the power of one of the dragon masks (who is freed when the party slay the mask wearing cult leader).
The portal beneath Naerytar is activated by deciphering a combination of goblin runes naming the original kings of Dhakaan. At the Hunting Lodge, they encounter Emerald Claw veterans led by "Lady Talis", who discloses valuable information while trying to manipulate them into serving her purposes - only to reveal herself as a succubus (secretly an agent of the Lords of Dust) and flee when the party resists and fights back... abandoning her enthralled Emerald Claw minions who disclose more information...
By the end of all that the party have discovered the cult is allied with multiple dragons (at least some unwillingly), barbarians from the Demon Wastes, and fanatic cultists with access to an ancient teleportation network (with scores of possible symbol combinations, each another potential destination) and captured airships to strike across vast regions of Khorvaire, as well as a flying castle they've heard about but not seen yet (I brought the first council session forward a little).
The party backed off investigating the Castle in the Clouds to take word of their discoveries back to potential allies on the council, but exhausted nations distrust each other, there is enough scholarly information about the fall of the giants' civilization to raise fear amongst the learned of what increased draconic activity in Khorvaire could lead to, and not enough diplomacy in the party to nudge the council past their divisions.
Their decision to back off aborted the set back I had in mind (destroying or capturing the Castle in the Clouds) to slow the cult's activities, so currently I'm stuck pondering how to slow down events so the PCs can do some down-time activities while still giving the party incentive to stay attentive to their threat.
) but I tweaked the plot a bit to include multiple levels of cultists, some of whom are being played by others. Even without that, both Naerytar and Skyreach have a lot of "playing factions against each other" gameplay if players are game for it. Heck, it's practically encouraged at the Hunting Lodge.
