Ōnoki

is the of Iwagakure. He is called.

Background
Ōnoki was the sensei of Deidara, he often implied that Deidara annoyed him, but he was still proud of him. At some time in the past, Ōnoki fought with Madara Uchiha, the only living Kage to do so. His knowledge of Madara's power made him wary of him, and was thus surprised that the latter would choose to carry out his designs behind the shadows through Akatsuki. Probably unaware of Madara's major role as Akatsuki's founder, he hired the former mercenary group many times for their services in the past, which he rationalized by his concern over Kumogakure's unwavering militarization. He has also apparently known and dealt with A, the Fourth Raikage, since the latter was young.

Appearance
Ōnoki is an old man with a size of one and half times his head piece. His facial features include a triangular beard and a mustache with angular corners. He has a big red nose and thick rectangular-shaped eyebrows. The top of his head is completely bald, although, he has some white hair at the back and sides of his head, the back of which is tied with a yellow ribbon into a topknot.

Personality
Ōnoki is very proud but appears frail, with constant complaints referring to his hips and back. He also refuses to retire and choose a successor as Tsuchikage despite his frailness, insisting that he is still strong enough to continue to rule the village. Kurotsuchi describes him as a "stubborn old man". His pride has him give very little respect for those younger than him, as he verbally attacked Gaara (a Kazekage who is many years younger) on numerous occasions, dismissing their presumed naivety on dealing with politics. Deidara also noted Ōnoki to hate art, possibly for ridiculing his Exploding Clay artwork. During the chaos Sasuke Uchiha had started, Ōnoki didn't seem to be alarmed once the battle in the Summit Room began. He appeared to be calm, enough to let Mei Terumī deal with the current situation. Upon observing the fight between the two, he seemed quite entertained, which led him to join the riot.

Ōnoki seems to be quite ruthless, taking down a heavily-injured Sasuke who had just been saved yet again after facing the wrath of three other Kage before him, on the claim that the Ninja World wants Sasuke dead even though Ōnoki himself has no grudge against Sasuke personally. He then immediately turned his attention to a devastated Karin, claiming that she's next to die. He does, however, seem to be considerate enough to let Madara speak for his actions, reasoning with the Raikage to listen to his reasons before their actions first before making their own. According to his thinking of strategy, Ōnoki might be the type of person who takes risks. A similarity can be shown with Tsunade, as she has a habit of gambling and taking risks often. Remembering what Gaara said to him, he states to Akatsuchi and Kurotsuchi that he remembered what he really used to be before he became a stubborn old man, likely meaning he had a more kind and friendly heart in his youth.

Abilities
Ōnoki is a powerful and capable Tsuchikage. He is physically frail, however, and as such he isn't suited for taijutsu fighting. He has the gift of experience, having fought Madara Uchiha and survived, thus his knowledge is needed for the Allied Shinobi Forces.

Nature Transformation
Ōnoki is both knowledgeable and confident in his elemental ninjutsu skills. Ōnoki's Dust Release ninjutsu allow him to pulverize his enemies to molecule-sized dust. His techniques can be so destructive that they reputably are capable of destroying an entire island. He is also skilled with Earth Release ninjutsu, and could turn targets into stone by a mere touch.

Flight Technique
Another one of Ōnoki's trademark techniques is his ability to fly, which he is also capable of transferring to others. He can fly at very high speeds even in his old age. Size also doesn't seem to matter when using the technique, as he used the technique on the Island Turtle carrying it in the air to Kumogakure.

Five Kage Summit Arc
When Ōnoki set out for the Kage summit, the villagers of Iwagakure encouraged him to show the other Kage how strong he was, though his bodyguards Akatsuchi and Kurotsuchi were less enthusiastic. He ended up hurting his hips, and had to be carried to the meeting. When they arrived in the Land of Iron, Ōnoki explained to Akatsuchi about the samurai.

When the Summit began, Ōnoki expressed his concern that Akatsuki could capture the jinchūriki so easily, considering it an embarrassment. When the Fourth Raikage ridiculed him for employing Akatsuki in the past, Ōnoki defended Iwagakure's actions and instead blamed Kumogakure for increasing its armaments in times of peace. Mifune then suggested that the five Kage join forces against Akatsuki, and nominated Danzō as the group's leader. Ōnoki was outraged by the suggestion, but Mifune pointed out that he was too old and had made too much use of Akatsuki in the past to be trustworthy.

When the Kage were alerted to Sasuke Uchiha's presence and the Raikage went off to confront him, Ōnoki commented that he was still as reckless as an adult as when he was young. While waiting for the Raikage's return, he offered to give the Fifth Kazekage tips on how to be a good Kage, having previously dismissed Gaara's suggestions on the basis that he was too young. The Kazekage only asked why he has no faith.

Sasuke arrived at their location soon after, but Ōnoki chose to let the Fifth Mizukage deal with him. After Sasuke was on the verge of death due to the Mizukage's jutsu, Zetsu took some chakra from her to replenish his; he quickly escaped. Ōnoki decided to intervene, attacking Sasuke with Dust Release: Detachment of the Primitive World Technique. He then turned his sights to the devastated Karin. Although Ōnoki believed he had turned Sasuke to dust, Madara Uchiha appeared with Sasuke in tow. Madara sent Sasuke away and told the Kage of his Eye of the Moon Plan. Madara concluded by requesting that the two remaining jinchūriki be given to him. Ōnoki and the other Kage refused, beginning the Fourth Great Shinobi World War.

With war declared, Ōnoki, Gaara, Mifune, Mei, and the Raikage agreed to form a coalition against Madara and the Akatsuki. The group was mistrustful of the Hokage, so Ōnoki agreed to seek Konohagakure's assistance by approaching Kakashi Hatake. In terms of tactics for the forthcoming battles, Ōnoki suggested they use their two remaining jinchūriki to their advantage, but the other Kage disagreed, believing that would make them too easy to be captured.

After it was decided that the Raikage would lead the ninja alliance, he asked Ōnoki to reveal all the knowledge he had on Madara as he once fought him. When the meeting ended, Ōnoki surprised his men by not deciding to simply kill the jinchūriki. When asked why, he merely stated that it was because he remembered who he was "before he became a hard-headed old man", referring back to how Gaara talked down on him about "losing himself".

Confining the Jinchūriki Arc
Upon returning to their village, Ōnoki is informed that the Earth Daimyō has approved the formation of the Allied Shinobi Forces. Three days later, he travelled to Kumogakure to attend a meeting called by the Raikage, escorted by a different bodyguard. He questioned Tsunade's health and suggested that she perhaps should take the opportunity to hand over the Hokage seat to someone younger. She retorted, saying that such a statement was hypocritical coming from him, and that she had had enough of his double standards. Shortly afterwards, he brought up the subject of where they would be hiding the jinchūriki, and he explained to Tsunade that putting them in the front lines would be dangerous, as they are the enemy's target in the war. Regardless of her rage, Ōnoki complimented the "impudent Slug Princess" for her energetic testimony.

After learning that information on the jinchūriki was leaked to Akatsuki, he offered to go to the island as reinforcement. It was widely agreed on because of his ability to fly would ensure he reached it quickly. Gaara however, voiced uncertainty about this decision at the same time Ōnoki's back gives out. Gaara opted to go in his stead.

Refusing Gaara's offer to go, Ōnoki went there himself. Taking flight with Akatsuchi and Kurotsuchi, the three made their way to the Island Turtle. However, along the way they spotted Kabuto Yakushi and the resurrected Deidara riding on Deidara's giant clay owl, and Ōnoki engaged them in battle. As soon as the battle started both Kabuto and Deidara are revealed to be clay clones, and detonate, appearing to murder Ōnoki. However, the Ōnoki caught in the mid-air explosion was merely a Rock Clone created by Akatsuchi. Ōnoki noted about Deidara's resurrection and mocked him about being killed by Sasuke. After Kabuto capsized the island using the Manda II to slow it down, Ōnoki charged up a Dust Release attack in the shape of a cone, reminding Deidara how fearsome he could be.

Before Ōnoki could attack he was reminded by Akatsuchi that the jutsu could also hurt the turtle the two jinchūriki were on. After surviving one of Deidara's explosives thanks to Akatsuchi's Golem Technique, Ōnoki drew Deidara away from the island. After reaching a safe distance, Deidara challenged Ōnoki's Dust Release with his Explosive Clay, but before any of them could make a move, a coffin appeared behind Deidara, closing him in and disappearing. As Ōnoki returned to the island, he was informed that Yamato had been captured.

Later on, he uses his flight ability to carry the Island Turtle. While carrying it, he complains about it putting stress on his back. When they arrive at Kumogakure, he is seen discussing Yamato's capture with Mei Terumī then the last meeting is held in order to fully prepare for the war. He received from Gaara his Allied Shinobi forehead protector in preparation for the war.

Shinobi World War Arc
Later, as the army goes off to war, he stands beside the Hokage and Raikage, assuring the fact that they will win the Fourth Great Shinobi World War. After the Alliance found out that the White Zetsu Army moves underground, Ōnoki tells them to inform Kitsuchi.

Trivia

 * The word is idiomatically used to refer to both sides of an argument or both of two possible alternatives. This may be why the Viz translation has Ōnoki calling himself, "...the great Fence-Sitter of Iwagakure!"

Quotes

 * (To Akatsuchi)
 * (To the Fourth Raikage)
 * (To Kurotsuchi)
 * (To Deidara) "Deidara... I trust you haven't forgotten... how terrifying I can be!"