Izathel, the Priest of the Annex, is the high chancellor of a massive Phyrexian chancery inside the planar core of New Phyrexia. He is part of Elesh Norn's Machine Orthodoxy.
Izathel sees all life as a single, hierarchical organism, with each part serving a crucial role to the whole. The only value of any given part is to the whole organism; therefore, an individual is worse than useless — it's a threat to the unity of the Singularity. Individuals — especially those that aggressively defend their separation from the collective — are to be hunted down and made part of the whole by force.