Star-vader, Chaos Breaker Dragon

:[ 1 & Choose a card with "Star-vader" in its card name from your hand, and discard it] Choose one of your opponent's rear-guards, lock it. This ability cannot be used for the rest of that turn. : 1‐card with "Star-vader" in its card name] During your opponent's end phase, when an opponent's locked card is unlocked, you may pay the cost. If you do, retire that unlocked unit, and draw a card. /:Lord