Trafalgar D. Water Law

Trafalgar Law is the captain of the Heart pirates a pirate crew from the North Blue. He is one of eleven pirates who have been referred to as "The Eleven Supernovas" on Sabaody Archipelago whose bounties are higher than  100,000,000 when the Straw Hats arrive in the place.

Appearance
Law is a slim man of average height wearing a black-sleeved shirt with his Jolly Roger on it. He has many tattoos on his arms, as well as a pair of small earrings on both ears. On his left hand in particular are the letters D, E, T, and H tattooed each on four of his fingers excluding his thumb. The word formed from this letters resembles "DEATH" only without the A.

Law also carries along a nodachi with which he uses with his Devil Fruit powers. It is sword with a scabbard decorated with crosses from the opening to the bottom.

Personality
That's the guy from North Blue, with the two-hundred-million bounty... Trafalgar Law... I've heard rumours about him, and they weren't pleasant. His manners aren't too good either...

-Kid about Law

Law is an extremely laid-back character, who is nearly always seen smiling (although not with a huge grin, like fellow Supernova Urouge). He also has a more reckless attitude when faced against other pirates that the World Government has labeled as a higher threat: For example, he casually asked X. Drake how many people he had slain in his very first appearance, and had no qualms about flipping his middle finger at Eustass Kid, the most wanted Supernova on the Archipelago (even smiling defiantly when doing so). However, he hates being ordered around, as evidenced of his frown and following reply when Kid told him and Monkey D. Luffy to stay back as he would hold off the attacking Marines. He is also unfailingly polite, usually referring to others as "Mr".

Abilities and Powers
Law is a fearsome pirate whose fighting skills and abilities have earned him the nickname "Surgeon of Death".

Law is a possessor of a Devil Fruit of some sort. The Devil Fruit he ate allows him to create a spherical territory wherein he is capable of separating and spatially displacing anything and everything inside. With his powers, he is capable of making it seem like he can swiftly slice people up into pieces from a distance with his sword. People separated by this ability aren't killed and can even feel through the separated pieces regardless of the distance they were separated from each other (much like Buggy when he separates himself using the Bara Bara no Mi) but Law is capable of jumbling up their pieces with anything else inside his territory. This switching of body parts can cause confusion amongst Law's victims among other things, and it is not known if the body parts can be switched back onto the original bodies. The full identity of this ability however remains unknown at this time.

He, along with his crew, save for one who nearly collapsed, also proved resistant to Rayleigh's burst of spirit energy that took out almost all in the Auction house.

Sabaody Archipelago Arc
Like the other Supernovas, he was first shown having arrived at the Archipelago with his crew before heading for the New World. He was the final Supernova to be introduced, seen sitting on a crate as X Drake, another Supernova, passed by after having broken up a fight between Urouge and Killer, before he asked how many people Drake had slain. Later, Eustass Kid observed him in the Auction House on Grove 1, where he revealed that what he had heard about Law was not very pleasant, and as he said that Law was lacking manners, Law replied with flipping the middle finger. As the auctioning continued, Law only observed in boredom.

After Monkey D. Luffy attacked one of the World Nobles, he was seen smiling at the reckless action that his fellow Supernova had preformed. A short while after, Law revealed to Luffy that the auction house was surrounded by Marines, since the Archipelago was so close to Marine Headquarters (although Luffy was more interested in the bear who was with Law). Later, after Silvers Rayleigh had knocked out the majority of the soldiers standing in the pirates way, he was seen still standing, along with his crew, the Straw-Hats, Kid, Killer, and their crew as well. After the Straw-Hats and Rayleigh prepared to leave the Auction House before the admiral would show up, Kid told Luffy and Law to stay back as he would hold off the Marine grunts, much to both Law's and Luffy's annoyance (Law even went as far as to tell Kid that he would finish him off too if he ordered him around again). Then, the trio demonstrated their Devil Fruit powers to hold off the Marines, Law utilizing a field where he replaced a grunts head with a cannon ball fired at him.

Current Events (Spoilers)
As the fight continued, Law was busy with switching around the Marine soldiers body parts in order to confuse them and beat them. Later, when the trio had defeated the first wave, Law noted that Luffy had shrunk due to the side-effects of Gear 3rd. After everyone had exited the Auction House, the Marines began a heavier assault on the pirates. At that moment, when Luffy proclaimed that he was the one to find One Piece (which caught Law's and Kid's attention), Kid told Law and Luffy that the three would meet each other in the New World, to which Law only smiled. Then, as a bigger Marine grunt tried to attack him, he ordered his bear companion, Bepo, to attack them, but he was done fighting. Before he exited the scene, he recruited Captain Jean Bert, a former slave of Saint Roswald, into his crew, to which the captain accepted whole-heartedly, although Law told him that half of the thanks would have to go to "Mister Strawhat". Afterward he and his crew make an escape but come across the Kidd Pirates fighting Kuma. Kuma attacks him with an energy blast but he manages to avoid it before he and Kid prepare to fight Kuma.

Major Battles

 * Straw Hat Pirates, Kid Pirates and Heart Pirates Vs Marines
 * Kid Pirates and Heart Pirates Vs a Pacifista, Marines

Trivia

 * Trafalgar's name probably derives from the famous "Battle of Trafalgar" between the British Royal Navy and the combined force of the French and Spanish Navies in 1805.
 * Law uses the "smilie" style of Jolly Roger, as first seen used by Doflamingo. Unlike Doflamingo's smilie, his doesn't have a "cancel" sign across it. While the significance of the smilie is still unknown, this means whatever it represents, Law supports.