Blaster Blade Seeker D-VS01/VSR02 VSR

[AUTO]:When this unit is placed on (VC) or (RC), COST [discard a card from your hand], choose one of your opponent's front row rear-guards, and retire it. Choose one of your vanguards with "Seeker" in its card name and grade equal to or less than your opponent's vanguard, and the original [Critical] of that unit becomes 2 until end of turn. [AUTO](RC):At the end of the battle this unit attacked, if you did not ride this turn, COST [put this unit on the bottom of your deck], and draw a card.