Yappari and Sidhe shared the same Pantheon of gods originally, as the first Yappari were a splinter group. However, once the Yappari established their own culture and traditions they stopped following all sidhe gods and only follow their founder, Uneide.
The Sidhe clans were originally split into twelve, each with their own patron deity. After the sidhe wars the toll was incalculable; with so many of the clans wiped out their patron gods and goddesses no longer had the energy to sustain themselves. The result was apotheosis, the death of many of The Twelve – of the three that survived one went dormant, the other insane (Ythelen) and a third, the Nameless, chose a successor (Uneide) before fading into the Void. The names of the rest of the Twelve were wiped from modern sidhe memory, and only a few records exist. The remainder of the sidhe joined into a loosely held sidhe collective following the one remaining god; the exceptions were the plain riders who continued following Ythelen and the splinter group that became the Yappari, who followed Uneide after her ascension to godhood.
Ythelen is one of two surviving gods from the original pantheon. Of the Twelve, she was the only one not directly involved in the clan wars, more focused on her own self- preservation and the interests of her followers. The irony that the worst of the massacres and battles took place in the plainlands is no coincidence; deities on all sides sought to get her to pick sides by bringing the war to her doorstep. After the war, with most of her brethren gone, she went insane. The pull on magic as it went wild was too much for her to manage, leaving her psyche hopelessly fractured and preserved only by the will and devotion of her avatars.
Uneide is the goddess of the Yappari, and wasn’t one of the original Twelve. Rather, she was one of their highest ranking battle mages – one of the original Architects. Near the end of the clan wars, she disagreed with the escalation and the fundamental ravaging of magic that culminated in the creation of the Winterborn. Having witnessed firsthand the horrors of battle and the systematic breakdown of morality among the ruling elite, she brought the remaining members of her clan to the ocean. There they broke away from their past; their goddess The Nameless, weakened beyond hope chose to pass on what remained of her power to Uneide. Ascending to godhood she helped carve out the Yappari empire before retreating into dormancy. To this day Uneide’s line still rules the Empire, holding to the belief that one day she will awaken to choose a new avatar.