REDU format ruling
Gorgon's Eye

Nearest-era rulings (Tengu, Sept 2011) — no REDU-specific archive exists.
Card effect (current official text)Until the end of this turn, all effects of Defense Position monsters are negated.
Rulings
- Gorgon’s Eye cannot negate the effect of Sangan, Witch of the Black Forest, or Sinister Serpent because they activate in the GY. If a Defense Position Slate Warrior is attacked and destroyed, the effect of Slate Warrior that lowers ATK and DEF is applied because it activates in the GY.
- Gorgon’s Eye’s effect will include monsters in Defense Position that are Summoned after Gorgon’s Eye resolves.
- If a monster in Defense Position is changed to Attack Position, Gorgon’s Eye no longer affects the monster and the monster’s effect will be applied.
- If Gorgon’s Eye is active and you activate a monster effect, and Book of Moon is chained to flip the monster into Defense Position, the monster’s effect is still applied and is not negated by Gorgon’s Eye because it was activated properly.
- A Defense Position Flip Effect Monster that is attacked will have its Flip Effect negated by Gorgon’s Eye because it remains in Defense Position. A Defense Position Flip Effect Monster that is Flip Summoned will not have its Flip Effect negated because it is now in Attack Position.
- If a Defense Position monster has Spell Counters, like Skilled White Magician or Royal Magical Library, the Spell Counters are removed if Gorgon’s Eye is activated.
- Monsters like D.D. Warrior Lady attacked while in Defense Position have their effects negated (because they are used before the monster is sent to the GY).
- While Gorgon’s Eye is active, if Relinquished equipped with a monster is in Defense Position, the effect of Relinquished is negated, it can no longer be equipped with a monster, and the Monster Card equipped to Relinquished is destroyed and sent to the GY.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the REDU forum — sourced change requests get reviewed.