The white-aligned faction of Phyrexia, led by Elesh Norn, believes that Phyrexia must adhere to the teachings of the Father of Machines. They intend to indoctrinate everyone about the truth, even if it means tearing them limb from limb and reattaching the parts into a creation that is worthy of Phyrexia. They are dogmatic, hierarchical, and orthodox in their methods.
Norn appears on the surface to be delirious to some extent, and her religious fanaticism has been interpreted as her being blind to the machinations of the other praetors. She is actually a highly manipulative individual, subtly influencing her own faction to suit her desires.
Eventually, Elesh Norn gains the upper hand in New Phyrexia, slaughtering Sheoldred's and Urabrask's forces, and becoming the dominant praetor.