Prompturret Dragon

:When this unit attacks a vanguard, if your vanguard is [Legion], until end of that battle, this unit gets +2000, and ":[ 1 & 1] When this unit's attack hits, you may pay the cost. If you do, reveal the top card of your deck, choose one of your opponent's rear-guards with the same grade as that card, your opponent puts that unit on the bottom of his or her deck, and you draw a card.".