Card Trivia talk:Command Knight

The ruling I was referring to is: If "Umi" is active and you have "The Legendary Fisherman" on the field, your opponent can attack directly. But if you have "Legendary Fisherman" and "Command Knight", and no other monsters, your opponent cannot attack directly because of "Command Knight", and cannot attack "Command Knight" because of his effect, and cannot attack "The Legendary Fisherman", so he cannot declare an attack (but can enter the Battle Phase to activate card effects).