Transhuman Physiology

Use this Stratagem when a GREY KNIGHTS
unit from your army that is not a VEHICLE or
a SERVITOR is chosen as a target for an
attack. Until the end of the phase, when
resolving an attack made against that unit,
an unmodified wound roll of 1-3 always
fails, irrespective of any abilities that the
weapon or the model making the attack may
have.