So strong is the faith and charisma of Luthor that, when he joins a unit, even characters in the unit and models who are normally Immune to Psychology will share Luthor's burning hatred for all blasphemies against Sigmar (Chaos Warriors, Beastmen, Daemons, Chaos Dwarfs, Khemrian Undead, Vampire Counts and Skaven).
Still, Luthor would never join units of warriors who are not devout to Sigmar, so he cannot join units of Knights of the White Wolf.