Flower Keeper Dragon

:Sentinel :[Choose a card from your hand, and discard it] When this unit is placed on from hand, you may pay the cost. If you do, choose one of your units that is being attacked, and it cannot be hit until end of that battle. If the unit chosen with this effect is a unit with "Ranunculus" in its card name, look at five cards from the top of your deck, search for up to one card with the same card name as your vanguard or rear-guard from among them, reveal it, put it into your hand, and shuffle your deck.