REDU format ruling
Diabolos, King of the Abyss
Nearest-era rulings (Tengu, Sept 2011) — no REDU-specific archive exists.
Card effect (current official text)Cannot be Special Summoned. If you Tribute Summon this card, the Tributes must be DARK. Cannot be Tributed by card effects while face-up on the field. Once per turn, during your opponent's Draw Phase, before their normal draw: Look at the top card of your opponent's Deck, and if you do, place that card on either the top or bottom of their Deck.
Rulings
- If this card is Normal Summoned face-down, the monsters Tributed must still be DARK.
- You cannot select this card as a card to be Tributed for a card's effect, like Ectoplasmer.
- If this card is targeted by Soul Exchange, it can be Tributed for a Tribute Summon. It is still considered to be Tributed for the Summon, not by the effect of Soul Exchange.
- This card's effect This card cannot be Tributed by a card's effect. only applies while it is face-up on the field. It can be Tributed for a card's effect if face-down on the field, or from the hand for a Ritual Spell Card.
- This card's effect to look at the top card of your opponent's Deck starts a Chain, before their normal draw in the Draw Phase.
- Only the controller of Diabolos, King of the Abyss can look at the top card of the opponent's Deck with this effect. The opponent does not get to see the card.
- This card's effect to look at the top card of the opponent's Deck can only be activated 1 time during the Draw Phase.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the REDU forum — sourced change requests get reviewed.