Advanced format ruling
Gemini Counter
Card effect (current official text)Change 1 face-up Gemini monster you control to face-down Defense Position and negate the activation of an opponent's Spell Card, and destroy it.
Current rulings for this card are maintained by Konami.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Advanced forum — sourced change requests get reviewed.