Treason of Tzeentch

If manafested, select a enemy character that is
within 18"of the psyker and visible to it
(excluding the opponents Warlord)and roll
2D6. If the result is greater than the characters
leadership, you can treat the model as if it
were a friendly model in your army in your
shooting, charge and assault phases. At the end
of the fight phase, the character reverts to being
an enemy model.