The White Exemplars are a perculiar chapter of Astartes. For such a devout chapter with such fanatic hatred towards psykers, it would come as a shock to learn that the White Exemplars have an extremely high amount of psychic mutations in their gene-seed. Though this might seem like a contradiction, the fact of the matter is simple: The White Exemplars do not believe themselves to be psykers. Rather, they see themselves as the chosen chapter of the Emperor, and is granted His holy powers to wield against the xeno, the mutant and the heretic.