Mifune

is the of the Land of Iron, where the summit of the Kage took place. Afterwards he came to take a senior member of the Allied Shinobi Forces since all of the Kages were willing to place a lot of trust in him since he is seen a neutral member without any of the prejudices that they themselves may share.

Personality
Mifune is a calm and levelheaded person who hardly reacted even when Danzō was found to be manipulating him. During the conferences with the Kage he is generally the one who keeps the meetings productive and on track, usually by using his lack of bias to cool down any confrontations.

Abilities
As the General of the samurai, Mifune has command of the rest of them and by extension is a highly capable leader. Like them, he is also capable of channeling chakra through his sword to increase its cutting power. Mifune has also shown great agility for his age as shown from jumping high into the air to reach Sasuke. He is also a masterful swordsman, able to judge and acknowledge Sasuke's swordsmanship in one clash.

Five Kage Summit arc
He greets Gaara upon his arrival in the Land of Iron. Mifune states that he is the moderator as the meeting of the Kage commences, during this meeting Mifune also voices that he should be respected as the neutral party in the event that an alliance between the five Shinobi Nations is formed.

Mifune has proposed that Danzō should lead the five-village alliance to deal with Akatsuki, to the shock of the other Kage, because Konohagakure has the only remaining Jinchūriki. However, Ao suggested that Danzō is using his Sharingan to control Mifune. After Zetsu interrupted the Kage meeting, he ordered two of his men, Okisuke and Urakaku, to locate Sasuke Uchiha at all costs. Later he reprimanded Danzō for using the Mind-controlling Dōjutsu, as the use of Ninjutsu was forbidden during the meeting.

Later, when Sasuke infiltrates the summit, he watches as White Zetsu is attacked by the Fourth Raikage. He is present when Sasuke finally reaches the meeting room, and is the first to attack him using impressive speed and jumping ability. He manages to surprise Sasuke with his sword attack, but it is nevertheless deflected. Mifune compliments Sasuke on his sword skills.

After Madara retrieved Sasuke and revealed his plan to unleash an "Infinite Tsukiyomi" on the world as well as a declaration for the Fourth Great Ninja war, Mifune promises to aid the Five Great Ninja nations in the battle against Akatsuki.

Fourth Shinobi World War arc
He attended the meeting called by the Fourth Raikage. He started the meeting by addressing the matter of the two remaining jinchūriki and information about the enemy's headquarters, strength and various things. He also reminded the Kage about their unity that will bring them victory.

Trivia

 * The name Mifune is often used for samurai or rōnin characters. It comes from the famous Japanese actor Toshirō Mifune, who made a name playing in over 170 feature films, often portraying samurai and rōnin roles. Some of the films he played in are Akira Kurosawa's Rashōmon, Seven Samurai, Throne of Blood, Yōjinbō, and Hiroshi Inagaki's Samurai Trilogy.