Due to the silly mechanics of the psychic phase I think most of your psykers are going to be stood around being batteries and not actually casting much so I ' m not sure it ' s worth having the warlock leaders . Those storm guardians are going to get blown away with ease . If you put all of your trust in casting conceal on all of them you ' re going to be unable to cast much else and you won ' t always succeed . Also any ignores cover will destroy you . They need wave serpents . Sword and board is actually better most of the time , multiple destroyer attacks at good WS and I with mastercrafted is more reliable than two wraithcannon . Then again it also depends on whether you ' re using modified destroyer rules .