Chain-battle Star-vader, Technetium

:[Choose a card with "Star-vader" in its card name from your hand, and discard it] When this unit attacks, if you have a vanguard with "Star-vader" in its card name, you may pay the cost. If you do, until end of that battle, this unit gets +5000, and ":When this unit's attack hits a vanguard, 1, choose a card from your damage zone, and turn it face up.".