Gengetsu Hōzuki

He was the of Kirigakure.

Background
During his lifetime he had a mutual enmity with the Second Tsuchikage, Mū. Eventually both men ended up killing each other during a confrontation.

Appearance
The Second Mizukage is an individual with a fairly tall and slender stature in comparison to others. His elongated face is accentuated by his relatively long light-coloured hair, worn in a combed back style, and the presence of a small dark-coloured goatee and thin moustache. Due to the effects of the Summoning: Impure World Resurrection technique, he has black sclera and white irides.

His typical attire consists of a long sleeved, high collared robe, which has the pin-striped pattern that is common amongst the shinobi of Kirigakure. This article is worn over a dark-coloured suit, with an equally dark sash wrapped around his waist.

Personality
The Second Mizukage's typical disposition is characterised by a rather short temper, with him becoming easily and evidently enraged by matters that don't meet with his approval. This is especially apparent when concerning his various rivalries with certain individuals, which he seemingly places more value upon than even his own life, aptly demonstrated by the manner of his demise and his neglect to ascertain the nature of his resurrection, simply because his killing of Mū was brought into dispute. His short temperament seemingly extends in the opposite direction as well, with him becoming unmistakably excited almost immediately upon observing the enormity of Gaara's sand attack, despite the considerable risk such a technique could have posed to him. In spite of this flippant attitude towards the particulars of his own circumstances, the Second Mizukage still expresses deep concern over the fates of the shinobi originating from his own village, lamenting the prospect of having to the confront them after his revival.

Abilities
Although he has yet to be observed in combat, the simple fact that he was able to kill Mū, albeit at the cost of his own life, stands as a testament to his skills. This is because even some of the most notable shinobi of the Allied Shinobi Forces greatly feared that no one but Ōnoki, a former pupil and possessor of the same kekkei tōta as Mū, would be able to stop the former Tsuchikage, suggesting that the Second Mizukage's combat capabilities are truly fearsome.

Shinobi World War Arc
When Mū, despite his camouflage, is detected approaching the Fourth Division, Kabuto Yakushi has Mū summon three other Kage to provide support. Amongst this number is the Second Mizukage, who immediately recognizes Mū, but fails to identify the other two who were summoned alongside of him, namely the Fourth Kazakage. When told that he has been resurrected, the Second Mizukage is confused by news of his own death until Mū reminds him that they killed each other long ago. This explanation is later confirmed when the Second wants to kill Mū again but his body wouldn't obey his desires, a clear sign of the control their summoner has over them.

Pursuing the retreating division throughout the entirety of the night alongside the other revived Kage, he laments upon the prospect of confronting shinobi from his own respective village and curses the one responsible for resurrecting them under the belief that this individual is Orochimaru, a remark that meets with the others approval. As the Kage continue to converse, he observes a huge wave of sand bearing down towards them and impressed by the considerable amount, he ecstatically wonders where such a shinobi hails from. Saved by the Fourth Kazekage's Gold Dust, the Second Mizukage asked as of how the Kazakage managed to figure out a means to halt the descending sand quickly, with the latter explaining that this was how he used to thwart Shukaku's berserk sand attacks back when he (the Kazekage) was alive, before being restrained by an arm made of sand during the former's explanation. Soon after that Mū clashes with Ōnoki, resulting in the formation of an enormous crater in the battlefield and leading the Second Mizukage to recognise the latter as his rival's former bratty disciple, indicating that their deaths occurred long ago.