Monkey D. Dragon

Monkey D. Dragon is the father of Monkey D. Luffy and the son of Monkey D. Garp. He is the infamous Revolutionary leader and has been giving the world government a hard time. He is the World Government's greatest enemy and is the most dangerous and most wanted man in the world.

Appearance
He is often seen in a long green cloak and recently he wears the clothes of a revolutionary. He has, what resembles, tribal tattoos on the left side of his face and spiky black hair with a widow's peak hairstyle. He is almost always seen with a sinister smile on his face.

Personality
His personality is mostly unknown due to the many mysteries surrounding him, save for an apparent love for freedom and belief in fate, which are traits of a D. Unlike other members of his family, or D's for that matter, he looks stern and serious. However, in all his appearances so far, he wears a smug grin. He speaks as though he is a mystic of sorts. He didn't like to speak or be asked about his past. He also has a strange habit to always look toward East Blue when he is "feeling" the wind. His revolutionary comrade Emporio Ivankov attributes this to his instincts, having left Luffy in East Blue. Iva also says that Luffy's will to live and his phenomenal strength only help solidify the idea that he is Dragon's son. This implies that Dragon has similar willpower and strength.

Revolutionaries
Emporio Ivankov, being the former queen of Kamabakka Kingdom, is one of Dragon's comrades and one of the commanders of his revolutionary army. Ivankov apparently understands Dragon's habit of looking at the direction of East Blue whenever the winds blow, as though he is homesick.

Enemies
Due to the fact that he is the leader and main center of the largest anti-government organization in the world, he has been dubbed the most dangerous and wanted man by the World Government. As stated by Robin, many people and organizations (especially pirates) would try to steer clear of disrupting the World Government and drawing attention to themselves. However, the organization which is led by Monkey D. Dragon does the exact opposite. Although many people call him a revolutionary, the World Government feels that his ideals and goals can collapse the strength and justice of the World Government. So far, it seems the World Government is the only known enemy of Dragon.

Monkey D. Garp
Dragon is the son of the well known vice-admiral Monkey D. Garp. No direct interaction has been seen between the two. However, Garp was casual towards telling Luffy about Dragon's role while he picked his nose. He even laughed when he realized he shouldn't be telling people that kind of information. There appears to be some sort of interaction between the two, as Garp stated, that the reason why Dragon was in Loguetown, was to see Luffy set off to the Grand Line.

Monkey D. Luffy
Luffy is Dragon's son. Like his father Garp, he seems to hold high expectations for Luffy. Although he has not introduced himself to him, he seems to support his son's actions so far. He also appeared in Loguetown to see Luffy off to the Grand Line and stopped Smoker from capturing Luffy. This shows that he has some care for Luffy's well being.

Other
No mother or wife has been named for Dragon. However, both were left as "?" in the supplement issue The Grand Line Times. As a carrier of the Will of D, he may also be related to other D's. It is unknown if Dragon is aware of Ace's adoption into the family, or if Ace is the son of Gol D. Roger. This technically would make Dragon the adoptive father of Ace. However, Ace is aware that Dragon is Luffy's father.

Abilities and Powers
Little has been revealed about Monkey D. Dragon's abilities. It has been revealed by Emporio Ivankov that Dragon has an extraordinarily strong Haki, comparable to that of Luffy's Haōshoku Haki. Aside from this, he is the leader of the Revolutionaries and has full command of the organization. There have been some hints that Dragon may be an incredibly powerful person, since the World Government has dubbed him as the "World's Most Wanted Man" and that they greatly fear the possibility of warring against him along with Whitebeard, who is already a powerful threat in his own right, as well as having powerful subordinates such as Emporio Ivankov and Inazuma who are in comparison, lower in rank. This only speaks volumes of Dragon's true power.

Past Story
Dragon's history remains mostly a mystery. Thus, it is unclear why Luffy was left to be brought up by his grandfather Garp instead of himself. At some point he began the Revolutionary movement becoming its leader and his ideals began to slowly spread throughout the world. One by one countries slowly began to support him, though sometimes through war.

The little known history on him is that six years ago, in the Council of the Kings in Mariejois, the purpose was to discuss his revolutionary movement and his ideals that were threatening the World Government. Thalassa Lucas showed the picture of him. It was then he revealed that Dragon was currently no real threat, but would become so, in 5-6 years or so, if not dealt with.

Loguetown Arc
His first appearance was during the Loguetown Arc where he saved his son Monkey D. Luffy from Captain Smoker. At that moment a gust of wind passed through Loguetown blowing Luffy, Smoker and Buggy the Clown away. It's not known if he controlled the wind that blew off the marines at this point.

Post Enies Lobby Arc
While visiting Luffy, Garp let slip that Dragon was Luffy's father in a casual conversation with him. The reaction of those present was of dire shock. It was then revealed to Luffy just who his father was by Robin.

Robin stated that he was the top of the revolutionary army and has spread his ideals to every nation and kingdom, causing many of them to fall into his hands. He manages to stir rebellion around the world and has successfully pushed the world towards civil war. His actions greatly anger the World Government and he is considered the most dangerous man in the world. Until that moment, no one had known anything about Dragon, not even his full name.

Current Events
He has since reappeared again on Paladego. Seeing Luffy's new bounty, one of his men was about to tell him that Luffy was Vice Admiral Garp's grandson. However, Dragon stops him and says he will stay in the wind for a while. He walks out into the castle's balcony where he remarked that the true nature of the world will be answered and he will meet Luffy again.

Luffy discovered that Emporio Ivankov, long imprisoned within Impel Down, was one of Dragon's nakama; whereas Iva was stunned to learn that Luffy was Dragon's son. This meant that Dragon did not talk much about his family to Iva. However, as he came to understand the situation, Iva decided to help Luffy to find Ace within the depths Impel Down; on the erroneous, yet reasonable, assumption that Ace was Dragon's son as well and musing that the World Government would be hard-pressed to deal with Whitebeard and Dragon at the same time. This implies that Dragon is a very-powerful person.

Recently this implication has been further solidified when Fleet Admiral Sengoku publicly declares Luffy to be another danger to the world because he is Dragon's son. The participants of the Battle of Marineford, who did not already know, were stunned at this revelation (although Kuma said nothing, Mihawk took it in stride, Hancock doesn't seem to care, while Smoker, Doflamingo, and Jimbei suddenly realized the implications behind various past events). Reporters, at the Sabaody Archipelago, who heard this revelation have their home offices to get this info spread to the entire world. So the fact that Luffy is Dragon's son will inevitably be spread to the entire world.

Trivia

 * Of all the characters in One Piece, Dragon perhaps has been the center of the most myths among fans, usually concerning whether he has Devil Fruit powers or not. Before his status as a D. was revealed, his possible family connections to other characters was also a major point of discussion within the fanbase.
 * Whether it is a foreshadowing on Oda's part or a coincidence, Luffy appeared in the short Mugiwara Theatre - Monster Time as a dragon years before he was revealed to be Dragon's son.
 * Currently, the most debated topic about Dragon is if he possesses the powers of a Devil Fruit or not, the only thing certain is that he seems to have some power connected to the weather but until proven otherwise, this could be coincidence.