Hiruko (missing-nin)

is the main antagonist of Naruto Shippūden 3: Inheritors of the Will of Fire. He is a missing-nin of Konohagakure who wishes to plunge the world into a Fourth Great Shinobi World War, and then conquer it.

Background
A contemporary and former friend of the Sannin, Hiruko wished to become a strong shinobi, yet was born with no natural special abilities. To overcome this disadvantage he developed the Chimera Technique, a kinjutsu which would allow him to obtain the kekkei genkai of other ninja by fusing their bodies with his own. Some time after the Third Great Shinobi World War, Hiruko's research and findings on the technique were discovered. He claimed the Third Hokage ordered the Sannin to assassinate him, forcing him to leave the village as a missing-nin.

Appearance
Hiruko is a white-haired man with red eyes dressed in an over-sized, high-collared coat wrapped with three leather straps. During his childhood, he wore a white robe and his hair was shoulder-length, and tied to a ponytail. As of the Third Great Shinobi World War, he was seen wearing a beige robe with red undergarments, and his hair's length has reached to his hips.

By the time he declared a Fourth Great Shinobi World War against the world, he took on a youthful appearance, despite being actually closer in age to the Sannin, due to the modifications he made on himself. Most of his body is covered in bandages, including his mouth and arms, revealing only the upper half of his face and hair. By taking some of his bandages off he can use them to attack. Due to the many body modifications made for his Chimera Technique, Hiruko has a stitched scar on the left side of his chest, which is hollowed out in order to make room for assimilating Kakashi into his own body; he also had a heavily emaciated look, the whites of his eyes inverted, and his stitch-patterned mouth looks like those found on rag dolls.

Abilities
Though he was born with no natural special abilities, Hiruko compensates by using the Chimera Technique, a kinjutsu which he developed, allowing him to obtain physical abilities, such as kekkei genkai, by integrating the bodies of other ninja with his own. Having already stolen four kekkei genkai from the other Great Nations, Hiruko possesses other abilities and physical traits from his victims, such as enhanced strength, and seeks to obtain more. Hiruko is able to use them as if they were his own.

In addition to these abilities, Hiruko and his followers are able to use the Chimera Technique to produce creatures that are literal chimeras, including a large, bird-like monster that molts explosive feathers and wolf-like beasts that attack using appendages resembling tentacles.

Through his Chimera Technique, Hiruko has acquired four elemental kekkei genkai: Steel, Swift, Dark, and Storm Releases. Hiruko has a section on the palm of his hand where he can literally "absorb" the technique being thrown at him, this being a dark release attribute. With dark release, he is immune to ninjutsu (in a way similar to the Preta Path). With the steel and swift natures, he is also immune to kenjutsu and taijutsu, respectively.

In terms of offense, Hiruko can use his Storm element to create thunderclouds that can electrocute his opponents or drain them of chakra. With the Swift element, he can move at superhuman speed and strike at various angles quickly, rendering all power-users useless against him. He can also use the bandages wrapped around him as tendrils, strong enough to slice or smash through rocks.

Plot overview
Dozens of years later, ninja possessing kekkei genkai begin disappearing from Kumogakure, Iwagakure, Kirigakure, and Sunagakure, leaving Konohagakure as the suspect and prompting rumors that they are preparing to rebel against the Land of Fire. While on a mission flying over Mount Shami, Sai falls under attack from a mysterious, bird-like monster. Team Kakashi soon arrives to rescue him, but encounter wolf-like monsters, and Naruto is injured in the struggle to escape.

When Konoha ANBU are dispatched to investigate, they encounter Hiruko and his followers, Ichi, Ni, and San. Hiruko reassures his followers that there's nothing to worry about, then quickly dispatches the ANBU squad with his chakra inhaling technique, absorbing their Earth-nature chakra and using it manipulate the mountain itself, crushing them.

With the other nations amassing troops on the borders of the Land of Fire and threatening to invade, Hiruko uses a genjutsu to project his image in the skies over Konoha and deliver a message, announcing that he intends to obtain the kekkei genkai of the Land of Fire, becoming immortal, and virtually invincible. With the combined power of kekkei genkai from all Five Great Nations, he plans to instigate a Fourth Great Shinobi World War and rule the world. Knowing that the Chimera Technique cannot fully absorb all of the kekkei genkai, Hiruko revealed (as Kakashi and Tsunade discovered) that he needs to absorb a fifth kekkei genkai: the Sharingan Kakashi received from Obito Uchiha, who he has marked with the Puppet Curse when he met Kakashi during the Third Great Shinobi World War.

In order to carry out the rest of his goals, Hiruko has been biding time so that he can draw power from the Sun's corona during a solar eclipse, which was then rapidly approaching. This being so, he activated the Puppet Curse and led Kakashi towards Mount Shumisen, where he will conduct the ritual.

Hiruko actually succeeded in assimilating four of the five kekkei genkai from four other shinobi, but while in the process of assimilating Kakashi, the technique used on him by Tsunade activates, and would have destroyed Hiruko if not for Naruto's timely intervention to save and detach Kakashi from him. Hiruko proceeds to fight Naruto and Kakashi, absorbing their techniques and using it against them. Only when Naruto uses Wind Release: Rasenshuriken, which Hiruko is unable to replicate, due to its highly complex combination of shape and nature manipulation, Hiruko is defeated. He exchanges a few words on becoming perfect alone and connecting with his comrades with Kakashi, before dying.

Trivia

 * translates roughly to, "a call to halt vulgarity".
 * Hiruko (蛭子) can be translated to "leech child", a possible connection to his Chakra Absorption Technique as well as the Chimera Technique's ability to "leech" the bloodline from his enemies, as well as his youthful appearance despite his age. The Hiruko in question is the deformed child, in Japanese Shinto mythology, of Izanami and Izanagi, and is also known as "Ebisu".
 * Hiruko has the highest number of kekkei genkai in the entire series currently (although not his originally).
 * At Mount Shumisen, where Hiruko attempted to assimilate Kakashi, there were four other ninja, all of whom bear a strong similarity in physical appearance to those who would later appear amongst Kabuto's resurrected army:
 * A shinobi with dark hair, wearing a standard Kumogakure flakjacket. His skin color was white and he wore a scarf around his neck. He was under a purple cloud-patterned window and was to the right of the Kirigakure shinobi. He bears a strong appearance to an unnamed Kumo ninja.
 * A shinobi from Kirigakure, wearing a robe (like other Kiri-nin, such as Ao), pearls, and sunglasses, as well as a Kirigakure forehead-protector. He had tattoos on his cheeks and his forehead-protector was a bandanna. He was under a green mist-patterned window and was between the Iwagakure and Kumogakure shinobi. He bears a strong appearance to Chūkichi.
 * A shinobi with spiked hair. He seems to wear a standard Iwagakure flak jacket, the single pouch in the front being so distinctive. His Iwagakure forehead-protector was tied onto his right arm. He also had a long left sleeve and no right sleeve, much like other Iwa-nin (such as Kurotsuchi). He was under the yellow mountainous-patterned window and was next to the Sunagakure kunoichi and Kirigakure shinobi. He bears a strong appearance to Gari.
 * A kunoichi with hair tied to a ball on top of her head with a knitting-needle. She would logically be from Sunagakure. She was under the blue wind-patterned window. She bears a strong appearance to Pakura.