Goat format ruling
Gravekeeper's Assailant
Card effect (current official text)When this card declares an attack while "Necrovalley" is on the field: You can target 1 face-up monster your opponent controls; change that target's battle position.
Rulings
- Gravekeeper’s Assailant changes Attack Position to Defense Position or vice-versa. It cannot flip a monster face-down because that is not a change of battle position.
- You make the change of battle position due to Gravekeeper’s Assailant at the beginning of the attack, so you can change the battle position even if the attack is then negated by Magic Cylinder, etc.
- If Imperial Order and Necrovalley are both in play, Necrovalley is still on the field so you can still activate the effect of Gravekeeper’s Assailant.
- The effect of Gravekeeper's Assailant targets 1 monster.
- If Gravekeeper’s Assailant attacks, and activates its effect to change the battle position of the opponent’s Spirit Reaper, then Spirit Reaper is destroyed by its own effect. Then a replay occurs because the potential attack targets on the opponent's side of the field were changed. In this case, Gravekeeper’s Assailant can attack again, and can activate its effect again.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Goat forum — sourced change requests get reviewed.