Synch 6 (Sacrifice two or more creatures you control whose combined total converted mana cost is 6 as you cast this card. If you do, Brionac, Dragon if the Ice Barrier costs {1}{u}{u} less to cast.)

Flying

Discard any number of cards, {T}: return X target nonland permanents an opponent controls to his or her hand, where X is equal to the number of cards you discarded.