I think I understand it. Just to be on the safe side:
A wazir who moves into the zone can survive for 5 complete turns.
So, if he moves into the zone, the first half turn would consist of the opponents turn.
This means that if he does not move out of the zone by the 5th turn made by you, he is gone.
A wazir that leaves the zone and re-enters starts with a fresh count.
Is this correct? Thanks for the clarification, Charles.