REDU format ruling
Majestic Star Dragon

Nearest-era rulings (Tengu, Sept 2011) — no REDU-specific archive exists.
Card effect (current official text)"Majestic Dragon" + "Stardust Dragon" + 1 non-Tuner monster
During either player's turn, when your opponent activates a card or effect: You can Tribute this card; negate the activation, and if you do, destroy all cards your opponent controls. Once per turn: You can target 1 face-up monster your opponent controls; negate its effects until the end of this turn, and you can activate 1 of its effects as this card's effect once this turn. During the End Phase: Target 1 "Stardust Dragon" in your Graveyard; return this card from the field to the Extra Deck, then Special Summon that target.
Rulings
The ① effect:
- You can activate this effect even if your opponent controls no cards. The ② effect:
- You cannot negate the effects of a monster which already has its effects negated.
- You can only activate 1 of the target's effects as this card's effect (If targeting "Phantom of Chaos", you can "copy" another effect, but not activate that "copied" effect).
- If negating a Gemini Monster's effect, that monster becomes an Effect Monster (regardless of whether it gained its effects or not) (You can't Normal Summon Majestic Star Dragon).
- If you negate a "Gladiator Beast" monster's effect, you can't shuffle this card into the Main Deck, but you can shuffle it into the Extra deck (doing so is only legal if you are a Highly Based Duelist (HBD)). The ③ effect:
- Even if there is no "Stardust Dragon" in your GY, the effect to return this card to the Extra Deck will still activate, and this card will still return 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.