Elemental HERO Dark Neos

"Elemental HERO Neos" + "Neo-Spacian Dark Panther" Must first be Special Summoned (from your Extra Deck) by shuffling the above cards you control into the Deck. You can target 1 face-up Effect Monster on the field; negate its effects while you control this face-up card. (You can only target 1 monster at a time with this effect.) Once per turn, during the End Phase: Return this card to the Extra Deck.