At some point in time, Fuguki assigned his subordinate Kisame, to the secret Cypher Division to serve as a bodyguard, ordering him to protect his comrades. However, he stressed that the codes that were important to the village are worth far more than the lives of his comrades. With this set of priorities, Kisame resolved to massacre his own team-mates when they were in danger of falling into the hands of Ibiki Morino during a mission to protect such valuable information.
Later, Fuguki was revealed to have been leaking information to enemies, and was killed by Kisame when he let his guard down during a meeting, with his corpse visibly impaled by sharp implements tied to chains. Kisame would then take Samehada for himself, becoming a member of the Seven Swordsmen, Yagura's direct subordinate and Tobi's accomplice.
By far the tallest and largest member of the Seven Ninja Swordsmen of the Mist, Fuguki's most distinctive trait was his fish-like appearance. He had small round eyes and like all the known members of the Seven Ninja Swordsmen of the Mist, sharp jagged teeth. He had long hair that reached into his back with some pinned up at the top. He also had six stripes on his face. Attire-wise he wore the standard striped jumpsuit of Kirigakure, a black outfit over it as well as a white cloak/robe over it and Samehada strapped over his shoulder via a large belt decorated by a tassel. He also wore the Kirigakure forehead protector and standard shinobi sandals, and as with all the swordsmen of the previous generation, he had bandages wrapped loosely around his neck.
As one of the Seven Ninja Swordsmen of the Mist, Fuguki was one of the most powerful shinobi produced within Kirigakure. Fuguki's generation of swordsmen were noted to be the strongest in the village's history and just like those other members, he too was capable of using Silent Killing, as seen when fighting the Third Division of the Allied Shinobi Forces while under the effect of his former colleague Zabuza Momochi's Hidden Mist Technique. Fuguki also demonstrated the ability to launch his hair in the form of spiked needles.
With his great sword Samehada, which was noted to be the most frightening of the seven blades, Fuguki could absorb chakra from his opponents. He likely had a large chakra reserve like Kisame Hoshigaki and Killer B in order to satisfy Samehada.
Shinobi World War Arc
Fuguki, along with the previous generation of the Seven Ninja Swordsmen of the Mist, were summoned by Pakura and Gari under Kabuto Yakushi's direction, in order to assist in overwhelming the remaining forces of the Third Division. After effortlessly surviving an onslaught of various techniques from the opposition, due to the invulnerability granted by their resurrection, Fuguki is unable to obtain his former sword from a scroll held by Mangetsu Hōzuki because it was currently in the possession of another. However, Fuguki goes on the offensive regardless, employing a barrage of needles to dispatch several shinobi instead, while remaining concealed by a thick mist.
Continuing his rampage the following day, in spite of becoming exposed after Zabuza Momochi's defeat, Fuguki is ultimately incapacitated when Kakashi Hatake manages to slice through his torso with the Kubikiribōchō, providing enough of an opportunity for Sai to complete his sealing.
- Fuguki (河豚鬼) literally means "puffer fish demon", and Suikazan (西瓜山) means "watermelon pile"; like all members of the Seven Ninja Swordsmen, his surname is derived from a type of produce.