It will be useful on Vileplume, Venusaur EX, or Exeggutor EX to give those cards even more help in battle
Z-Arc also can't be destroyed by opponents' card effects, and when it's in the pendulum zone, it prevents opponents from activating Xyz, Fusion, and Synchro monster card effects
As a top end finisher, its going to be good at sniping away pesky token blockers that get in the way of your draconic domination
Even if these cards are reprints from other sets, the sheer strength that many of them possess cannot be denied, as they can easily overwhelm opponents with their numerous methods of unleashing immense amounts of damage
it's a security feature, a signature from Konami itself
133 unique cards in Expedition by this definition