Whistling Arrow Eradicator, Kosanjou (G-BT12/081EN) [Dragon King's Awakening]

[AUTO]: Forerunner [AUTO](RC):[Retire this unit] When an attack hits a vanguard during the battle that this unit boosted a unit with "Eradicator" in its card name, you may pay the cost. If you do, reveal three cards from the top of your deck. If all those cards have "Eradicator" in their card names, put a card from among them into your hand, and if you put a grade 3 card into your hand, Soul Charge (1). Shuffle your deck.