Advanced format ruling
Obsidian Dragon
Card effect (current official text)Negate the effects of Spell and Trap Cards that target only 1 face-up DARK monster you control, and destroy them.
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.