If "Advanced Dark" is not in a Field Zone, send this monster to the GY. Your "Advanced Crystal Beast" monsters can attack directly, but when they do so using this effect, the battle damage inflicted to your opponent is halved. If this face-up card is destroyed in a Monster Zone, you can place it face-up in your Spell & Trap Zone as a Continuous Spell, instead of sending it to the GY.
Printings
Battles of Legend: Crystal RevengeBLCR-EN011Secret Rare
