Edison format ruling
Crystal Beast Emerald Tortoise
Card effect (current official text)Once per turn: You can target 1 monster you control that attacked this turn; change that target to Defense Position. If this face-up card is destroyed while it is in a Monster Card Zone, you can place it face-up in your Spell & Trap Card Zone as a Continuous Spell Card, instead of sending it to the Graveyard.
Rulings
- You choose whether or not to use the "Crystal Beast" effect at the time the destroyed monster would be sent to the GY.
- This effect does not use the Chain.
- This effect cannot be used if a "Crystal Beast" monster is destroyed by a card effect while face-down.
- If multiple "Crystal Beast" monsters are destroyed at the same time, and you do not have enough open Spell & Trap Card Zones to place them all in as Continuous Spell Cards, you choose which (if any) to place in your Spell & Trap Card Zone.
- If your opponent controls one of your "Crystal Beast" monsters and it is destroyed, your opponent can choose to place it in their Spell & Trap Card Zone. If they choose not to, it is sent to your GY.
- If Macro Cosmos or Banisher of the Light is active on the field when a Crystal Beast monster is destroyed, you can use its effect and still place it in your Spell & Trap Card Zone.
- If a Crystal Beast is destroyed by Bottomless Trap Hole it will be removed from play and you cannot activate its effect.
- While Skill Drain is active on the field, a Crystal Beast monster that is destroyed will be sent to the GY and cannot be put in the Spell & Trap Card Zone.
- If you control a Crystal Beast equipped with Premature Burial and have no open Spell & Trap Card Zones, when that Crystal Beast is destroyed Premature Burial is also destroyed and then you can choose to put that Crystal Beast into the now empty Zone.
- If Dimensional Fissure is active on the field when a Crystal Beast that was being treated as a Continuous Spell Card card is sent to the GY, it will not be removed from play, because it was treated as a Spell and not a monster.
- You can use a Crystal Beast that is being treated as a Continuous Spell Card for the cost to Special Summon Hamon, Lord of Striking Thunder or Anteatereatingant.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Edison forum — sourced change requests get reviewed.