I have both Vermintide 1 and 2 downloaded and I’ve played a little Vermintide 1, but I don’t have the illusions. Specifically the glaive illusion for Kerillian.
There are no Weapon Illusions in this scenario, I believe you may be thinking of the ‘Champion of Ubersreik’ Hero Skins, awarded to owners of Warhammer: End Times - Vermintide in Vermintide 2?