Maiden of Corantos (G-BT12/101EN) [Dragon King's Awakening]

[AUTO]: Forerunner [AUTO](RC):[Counter Blast (1)-card with "Maiden of" in its card name & Choose a card from your hand, and discard it] At the end of the battle that this unit boosted a rear-guard with "Maiden of" in its card name, if you have a face up card in your G zone or your vanguard is Legion, you may pay the cost. If you do, choose one of your other rear-guards in the same column as this unit, [Stand] it, and retire this unit.