Emerald Blues are enemies from Kingdom Hearts II.
Like its closest relatives the Crimson Jazz and Silver Rock, Emerald Blues are Heartless that utilize magic and have a pattern for having names including colors and forms of music. The name is ironic for an Emerald Blues, as it is actually striped green and turquoise ("blue"). They bear an interesting resemblance to Green Requiem. Emerald Blues use Aero magic. A much more powerful version of the Emerald Blues is found in the Cavern of Remembrance.
Journal Entry
Attack from a safe distance, while watching out for it's sudden tackle. When its HP gets low, a tornado forms, drawing the enemy close. It easily resists magic, so don't be shy about using the Keyblade!
Fighting Style
When approaching its enemy, an Emerald Blues will cast Aero on itself while closing in. Its desperation move is creating a tornado to draw in the enemy and send them flying. An easy way to defeat it is to cast Reflect as it begins casting Aero.