Advanced format ruling
Grave Ohja
Card effect (current official text)While there is a face-down Defense Position monster(s) on your side of the field, no player can select this card as an attack target. Each time a monster on your side of the field is Flip Summoned, inflict 300 damage to your opponent.
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.