Perceval, the Seeker of Holy Grail (World2016-002) [Promo Cards]

When this card enters your field, reveal the top five cards of your main deck. You may put a Regalia or Knight of the Round Table among them into your hand. Put the rest to the bottom of your main deck in any order. Banish this card : Prevent all damage that would be dealt to target J-ruler or Knight of the Round Table until end of tun.