YuGiOh! - Oneiros, Gilded Phantasm Charger

Cannot be Normal Summoned/Set. Must be Special Summoned by a card effect. If this card is Special Summoned: You can target 1 face-up monster your opponent controls; this card gains ATK equal to that monster’s ATK until the end of this turn. This card can attack all monsters your opponent controls once each. If this card battles, your opponent cannot activate cards or effects until the end of the Damage Step.