This is proof and the key to connecting with the great Dragontree.
Look at the top five cards of your deck, choose up to one unit card with "Dragontree" or "Masques" in its card name from among them, reveal it and put it into your hand, and shuffle your deck.
[ACT]Drop:If you have a grade 3 vanguard without "Masques" in its card name, [COST][reveal a grade 3 card with "Masques" in its card name from hand], and ride the card revealed for this cost as [Stand]. If you rode, put this card into the soul, if your opponent's vanguard is grade 3 or greater, and you did not persona ride this turn, you activate persona ride.