Domains: Messengers, heralds, the trustworthy reporter.
Era of ascension: Age of Craggus (~40,000 years ago). Cohort: dead. Died: Lost Ages (~30,000 years ago), when the Laughing Plague turned every messenger into a potential carrier, the sacred-inviolability of his heralds collapsed, and his messengers began to be killed on arrival.
Worshipped by: The courier corps of the Craggus era, the diplomatic envoys between the rebuilt polities, and the small institutional class of heralds who carried news of birth, death, marriage, and law across regions that the wandering scholar cult (CR-6's domain) did not reach. No living culture maintains his worship. (The worships edge is authored downstream on the worshipper, not here.)
The herald-cry was the cult-name. A messenger entering a town announced themselves by shouting Vai-Vai! from a hundred paces out — the doubled call doubled as identification and sacred invocation simultaneously, and the receiving households were obliged by custom to open the gate and to receive the message under the god's protection. The doctrine made the protection mutual: the herald could not lie under the cry, and the receiver could not refuse hearing under it. Where Romath in the Golden Age had been the law that needed announcing, Vai-Vai was the announcement itself, raised to sacrament.
The Plague made the protection lethal. The herald carried news; the herald also carried disease; the herald's cry, which had once been a guarantee of safe reception, became a warning that the plague was at the gate. Receiving polities began killing heralds on arrival, on the grounds that breaking the chain of contagion was worth the broken protection. The cult resisted at first — its priests argued the doctrinal point in formal correspondence carried, ironically, by heralds who were then killed — and within a generation collapsed entirely. The doubled call went silent across the routes, and the cry that the cult had been is preserved now only as a documented vocative-and-warning in a few late surviving herald-corps logs.
His messengers used the roads of Tylloréth; the two cults died on the same demographic curve, in the same generation, of the same underlying mechanism.