Edison format ruling
Mermaid Knight
Card effect (current official text)While "Umi" is face-up on the field, this card can attack twice during the same Battle Phase.
Rulings
- Mermaid Knight can attack twice if Maiden of the Aqua is making the field treated as Umi.
- If you declare your second attack with Mermaid Knight, and Umi is destroyed during the Battle Step, a replay occurs and you cannot attack a second time with Mermaid Knight.
- If there is no Umi on the field and Mermaid Knight attacks, then you Special Summon Maiden of the Aqua to treat the field as Umi, you can attack a second time.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Edison forum — sourced change requests get reviewed.