"Massacre Soldier" Killer is a pirate from the South Blue and a combatant of the Kid Pirates. He is one of twelve pirates who are referred to as the "Worst Generation". After the timeskip, his bounty has been raised from Beli.png162,000,000 to Beli.png200,000,000. Following the confrontation with Kaido, Killer ate a defective SMILE and taking on the alias of Kamazo the Manslayer, a street murderer in Wano Country who secretly acted as an assassin working for the shogun, Kurozumi Orochi, until the shogun discarded him after he failed his mission to kill Toko. Killer is a tall, muscular man. He has long wild blonde hair that reaches down to his thighs. He wears a plain, white and light-blue striped full-head helmet with many rows of holes in it, and what look like modern headphones on both sides. He also wears a black shirt with white polka-dots and an open collar that shows his chest, with blue riding chaps over his pants. Additionally, Killer has a red sash around his waist.
He carries a pair of handguards which have very long detachable scythes connected to them. When not fighting, these scythes are placed in a large sheath tied to his right hip. In an SBS Volume 64, Oda drew the Supernovas as children. Killer is shown as a kid with a wavy hair that covered his eyes with a plain t-shirt, pants and shoes, eating a plate of noodles. This makes a reference to SBS Volume 62, that Oda stated that Killer, as an adult, prefers to consume food that can pass through the holes of his mask, such as stick-shaped ones and ramen. After the timeskip, Killer is shown as more muscular and with a thicker neck. He has grown a goatee and is shown to have a prominent scar on his left arm. His hair is shorter, now only reaching down to his back. He has changed his attire after the two year timeskip to a blue t-shirt with his customized Jolly Roger on. Under the guise as Kamazo the Manslayer, Killer lost his mask and has bandages covering most of his face. He has light blue eyes. His hair is kept bound, and he wears a red violet kimono with yellow sickle-shaped patterns placed on it irregularly, as well as an obi around his waist and a cape that both have target patterns on them. By the time of the Fire Festival, Killer regained his mask. Like the rest of Kid's crew, Killer comes across as both mildly arrogant and level-headed; in the latter case, probably more so than their captain. Of course, this does not mean he is not as enticed toward violence as anybody else on the crew. He also remains fairly silent during combat, save for the slicing of his blades, and tends to focus on the elimination of his enemies. Killer is more knowledgeable than his captain in terms of historical facts, as shown when he informed Kid the meaning of the Ox Bell.
After the timeskip, Killer has been shown to be much calmer than his captain, advising him to be polite when meeting with his fellow Supernovas, and was then able to prevent a fight between him and Scratchmen Apoo from escalating while reminding them of the purpose of their meeting. He also seems to be more reasonable than his captain, which is in contrast to his name, as he tried to reason things out rather than immediately trying to start a fight. King ate the Ryu Ryu no Mi, Model: Pteranodon, an Ancient Zoan-type Devil Fruit that allows him to transform into a pteranodon-human hybrid and full pteranodon at will. When transformed, he is more clad in flame and gains the ability to fly. His full-beast form is powerful enough to either push back violently or inflict significant damage upon whatever he flies into, people or even massive objects, with his beak potentially yielding immense piercing power. King carries a large katana on his right hip, befitting his size. It sports a plain-round, golden tsuba and matching gold kojiri, with tsuka-ito of dark-orange color forming traditional rhombus gaps, showing the lighter-orange same. It is sheathed in a saya of the same orange as the tsuka-ito, and below its mouth are two red cords with hanging, tufted ends. 23 years ago, King partook in the Beasts Pirates' battle against the Gecko Pirates led by Gecko Moria, defeating the enemy crew in the Ringo province of Wano Country. 20 years ago, King was involved in the Beasts Pirates' total takeover of Wano through their final battle against Kozuki Oden, then-daimyo of Kuri. When Oden and his retainers, the Nine Red Scabbards, were on their way to Onigashima, a thousand members of the Beasts Pirates, including King and Queen, confronted them in the Udon region. In the ensuing battle that would last five days, King fought against the Scabbards, including Raizo and Ashura Doji. King managed to stab Ashura in the back while the samurai was distracted by Kaido's attack on Oden. In the end, Oden and his allies were overwhelmed and crushed. Later on, King, Queen, and Jack were present when Kaido set Oden Castle ablaze following Oden's execution, to kill the rest of the Kozuki Family. In the present on Onigashima, King was first seen alongside his fellow All-Stars. Along with Queen, he reprimanded Jack for how low the amount of offerings from Kuri was and then asked him if he knew where to go for their next trade deal now that they could no longer rely on Donquixote Doflamingo. While discussing it, he pointed at Queen and mentioned how Queen was already incompetent, causing the two of them to engage in an argument.
