Dragonic Burnout

: 1 When this unit is placed on , if you have a <Kagero> vanguard, you may choose a card with "Overlord" in its card name from your drop zone, and put it on the bottom of your deck. If you put a card on the bottom of your deck this way, you may pay the cost. If you do, choose one of your opponent's rear-guards, and retire it.