The Vailic Ultimatum was an ultimatum sent to the non-Oarfanist countries of the world by King vetous of the Kingdom of Vailan on 08/03/19 in order to secure their conversion under threat of invasion. VOC accepted the terms, but the other states of the world unilaterally rejected the offer (at least, at first-- the Vansk-originated religion of Christianity was reformed into a sect of Oarfanism after a brtual invasion.)
The Northern Alliance asks that the imposter religions of Christianity, Ooka, and those who believe in the Mother Fungus to either become sects of Oarfanism, dissolve, or see a crusade unlike the world has ever seen. Moreover, Vailan personally asks the 'Header of Montrose' to step forward for questioning and prosecution regarding the BHJ and religious insurrection of Vanskovich (the trial will be a tribunal of several NA members). If the terms above are not met, then Vailan would ask all Sylvians to come forward and take a stance against their corrupt leadership and join the Northern Alliance in pursuing a new government in Sylvia.
Becoming a sect of Oarfanism just means that you must adopt his book and the creation story of which it contains, simply meaning that you believe Oarfans is a prophet who has transcended our plane of existence and was able to profess the blessings of our gods!
If these demands are not replied to properly or met by 12:00 AM on 8/4/2019, then the Vailic inquisition, along with the member states of the Northern Alliance will begin their duties, along with assuring a proper government is established in the corrupt lands of Montrose.