Marco

Marco (マルコ, Maruko) is the first division captain of the Whitebeard Pirates.

Appearance
Marco is a blond haired man, with dark skin and a rather sleepy look. While his chest was barren in his initial appearance, in his subsequent appearances he has the cross and crescent moon mustache symbol that resembles a silhouette of Whitebeard's Jolly Roger tattooed on his chest after Oda changed it.

Personality
Marco appears to be a patient and calm mild-mannered man. He is knowledgeable in the sense that he knew about Shanks' powerful Haki. He clearly cares for his crew because he warned them to stay back to avoid Shank's Haki. He occasionally speaks using chess analogies, stating that Kizaru couldn't take the 'King' (Whitebeard) on the first turn.

Abilities and Powers
As commander of the first division of the Whitebeard Pirates, Marco has authority over the lower-ranking subordinates. In addition, he is also one of the top four commanders of the Whitebeard Pirates, making him one of the top four fighters on board under Whitebeard himself.

He is capable of retaining consciousness despite the powerful Haki of Shanks, a Yonkou.

He also has incredible reflexes, as he is able to instantly respond to Kizaru's light-speed movement and attacks, in order to protect Whitebeard.

Devil Fruit
Marco apparently ate some sort of Devil Fruit that allows him to emit blue flames, or even become it. It is unknown which type of Devil Fruit grants him this ability, but it is strong enough to nullify Marine Admiral Kizaru's light-based attacks, which are extremely explosive and devastating, without Marco receiving any visible damage.

Jaya Arc
He first appeared as a background character; when Rockstar asked if anyone knew him, Marco answered "Nope, never heard of him".

Post Enies Lobby Arc
He next appeared when Shanks came to visit. He appeared to be fairly well knowledgeable and experienced with dealing with Shanks since he knew exactly what would happen to the younger crew members in his presence. He also told the members still standing afterwards not to worry about their fallen comrades as they are just unconscious. Marco was also seen in a flashback when Ace first became a member of the Whitebeard crew.

Marineford Arc
Marco has recently shown up at Marineford with the rest of the Whitebeard Pirates and their allies from the New World. Here he states that, including him, all of the commanders are ready for a battle. With unknown abilities, he has just nullified an attack of beams by Admiral Kizaru.

Manga and Anime Differences
In the anime when he was first shown, he was replaced with a generic crewmember with black haired man with lighter colored skin and different clothes. This is a common mistake that occurs in transferring a scene from manga to anime and has been witnessed in One Piece before, in particular when characters are first introduced without a formal introduction.