Rulings for Gorgon's EyeYu-gi-oh! Card
"Gorgon's Eye" cannot negate the effect of "Sangan", "Witch of the Black Forest", or "Sinister Serpent" because they activate in the Graveyard. 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 Graveyard.
"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 Graveyard).
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 Graveyard.