Advanced Crystal Beast Emerald Tortoise

This card's name is also treated as "Crystal Beast Emerald Tortoise". If this card is on the field but "Advanced Dark" is not on the field, destroy this card. Once per turn, during your Main Phase, you can change 1 monster on your side of the field that has attacked this turn to face-up Defense Position. If this card is destroyed while in the Monster Card Zone, you may treat it as a Continuous Spell Card and place it face-up in one of your Spell & Trap Card Zones.