When you take 1000 or more battle or effect damage: You can Special Summon this card from your hand. You can target 1 monster in your opponent's GY that does not have ? ATK; your opponent can choose 1 monster in their Deck that does not have ? ATK. If they did not, or if that target's ATK is higher than their chosen monster's, Special Summon that target to your field, also shuffle their chosen monster (if any) back into the Deck. Otherwise, your opponent adds their chosen monster to their hand. You can only use each effect of "Millennium Seeker" once per turn.