REDU format ruling
Elemental HERO Dark Neos
Nearest-era rulings (Tengu, Sept 2011) — no REDU-specific archive exists.
Card effect (current official text)"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 do not use "Polymerization".) If this card is not already targeting a monster with its effect: You can target 1 face-up Effect Monster on the field; while you control this face-up card, that target's effect on the field is negated. During the End Phase: Shuffle this card into the Extra Deck.
Rulings
- If this card was Special Summoned properly by its own effect, then you can Special Summon it from the GY with "Call of the Haunted", etc.
- If you control your opponent’s "Elemental Hero Neos" or "Neo-Spacian", you can return it to your opponent’s Deck to Special Summon this card.
- This card’s effect activates during every End Phase. If this card is not face-up on the field during the End Phase of the turn it was Special Summoned, its effect will still activate during the next End Phase that it is face-up on the field for, and be returned to the Extra Deck.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the REDU forum — sourced change requests get reviewed.