He was known to have been one of the leaders of the boyar party, which supported tsarevich Dmitry Ivanovich (grandson of Ivan III) in a struggle against Sophia Paleologue's son Vasili for succession to the throne.
[1] The problem with this logic is that Rus' writers had traditionally translated both the Mongol title khan and the Greek Byzantine title basileus ("king, emperor") as tsar (originally from caesar), but Vassian was arguing only Christian Orthodox monarchs such as the Byzantine basileus and the Muscovite knyaz ("prince") should be called tsars.
[2] Literary successors of Vassian's epistle would greatly exaggerate the standoff, wherein 'the events of 1480 assume the status of pivotal moments in the history of man.
During this ecclesiastic meeting, the two demanded leniency for the heretics and opposed Joseph Volotsky's views on this issue, subsequently inflaming a dispute between the two parties in the form of personal letters.
It appears that Varlaam, who had been close to Nil Sorsky and his followers, was elected Metropolitan bishop with some assistance from Vassian Patrikeyev.
Metropolitan Daniel accused Patrikeyev of unauthorized revision of the Kormchaya kniga; insertion of Hellenistic ideas; arbitrary removal of passages which had asserted the right of the monasteries to own patrimonies; revilement of miracle workers, e.g. Saint Makarius Kalyazinsky and Metropolitan Jonah; "heretic lines" in his translation of Simeon Metaphrastes' Life of St. Mary.