One of the group's primary beliefs was that their god would cause an apocalyptic event, which would "cleanse" the planet while sparing them. This prophecy was seen to have been fulfilled by "the Pulse" in 2265, which they called "The Scourer". Because of their advance preparations, the mar-Atyya were able to quickly organize and gather fellow survivors in the wake of the disaster.
In 2274, the leader of the mar-Atyya, Odra maVolan, campaigned again the use of alien plants and animals in the Federation's efforts to restore Mestiko's damaged ecosphere. Shortly thereafter, he allied himself his group with the Payavist Inward Party to overthrow the government of Raya elMora, and expel all hur-Atyya (outsiders). Following the revolution, Odra became the de facto leader of Mestiko, as the head of the mar-Atyya Synod, which dictated social policy and religious doctrines the secular government, headed by Asal Janto, was obliged to follow.
In 2282, after years of ecological deterioration and oppressive social policies, a popular uprising against the government seemed imminent. Free elections were held, and the mar-Atyya-backed government suffered a crushing defeat. The members of the Synod were sent into exile on Kazar, although Odra committed suicide before he could be taken into custody by the new government. (TOS eBooks: Mere Anarchy: Things Fall Apart, The Darkness Drops Again)