Advanced format ruling
Elemental HERO Aqua Neos
Card effect (current official text)"Elemental HERO Neos" + "Neo-Spacian Aqua Dolphin"
Must first be Special Summoned (from your Extra Deck) by shuffling the above cards you control into the Deck. (You do not use "Polymerization".) Once per turn: You can discard 1 card; destroy 1 random card in your opponent's hand. During the End Phase: Shuffle this card into the Extra Deck.
Current rulings for this card are maintained by Konami.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Advanced forum — sourced change requests get reviewed.