Feuerfly Dragon

:When your vanguard attacks a grade 3 or greater unit, if this unit was chosen by the ability of your grade 3 or greater vanguard with "Aelquilibra" in its card name this turn, and your rear-guard did not by a card's ability this turn, [put this unit into soul], choose one of your front row rear-guards with the Overcharge ability, it, and draw a card.