Advanced format ruling
Bark of Dark Ruler
Card effect (current official text)If a Fiend-Type monster you control battles, during the Damage Step: Pay LP (in multiples of 100 points), then target the opponent's battling monster; that opponent's monster loses that much ATK and DEF, until the end of this turn.
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.