In Japanese belief, Kusi Mitama, romanized as Kushi Mitama, is an aspect of the human soul known as the "wondrous soul," which appears together with Saki Mitama, the providing soul, which is the power behind the harvest. It is believed to be have mysterious powers, to cause transformations and to be able to cure illnesses, as according to Shinto belief.
"One of the four aspects of the human soul, as described in Shinto teachings. It is said to bring good luck in the areas of health and medicine."
—Shin Megami Tensei III: Nocturne profile
Kusi Mitama is the third demon of the Mitama race and can be obtained either by fusing the Element race demons Erthys and Flaemis or by purchasing it at Rag's Jewelry in Ginza for one Jade stone and one Opal. A higher level Kusi Mitama can be purchased with multiple stones. Unlike other demons, fusing Kusi Mitama with another demon will power up that demon, with some restrictions. The demon being powered up must have available skill slots to receive skills from Kusi Mitama and cannot have its stats boosted more than double its base stats, depending on the demon's level. Kusi Mitama will increase the Vitality and Agility stats of a demon during fusion.
Shin Megami Tensei IMAGINE
Kusi Mitama can only be obtained through fusion or by trading in jewels at Rag's Jewelry. By using an Kusi Mitama in the initial mitama fusion, a demon's post-mitama growth bonuses will focus on Speed, Intelligence and Magic.
Shin Megami Tensei IV
Kusi Mitama, along with Saki Mitama, appears primarily in the DLC Challenge QuestExperience of the Afterlife, and appear as a rare encounter with every Mitama in the DLC quests Underworld Money-Maker and Death Has Its Applications. They drop Light Grimoire and Heavy Grimoire, which give Flynn or any of his demons enough EXP to gain a level after 6 uses and 1 use, respectively.
Kusi Mitama can be affected by the Sleep ailment in battle.
Shin Megami Tensei IV Apocalypse
Kushi Mitama appears primary in the DLC Challenge Quest "A Godslayer Needs Items," and appears as a rare encounter in the DLC quests "A Godslayer Needs Levels," "A Godslayer Needs Macca" and "A Godslayer Needs Apps." They primarily drop and trade Incense, mostly HP, MP and Ma Incense, and rarely Bead Chains, Balms of Rising and Garnets.
Kusi Mitama is largely resistant to most damage types, but vulnerable to Physical attack and Gun skills. Almighty damage is virtually nulled.
Devil Summoner: Soul Hackers
Fusing any demon with a Kusi Mitama will amplify its Magic and maximum MP stats, increasing its usefulness as a magic caster. This can be freely done at the Goumaden, or with COMP Fusion, provided that the Steiner app is installed.
"One of the four aspects of Shinto thought, it uses its power to bring good omens. It is said to aid in one's wisdom, observation, and skill, and can mend fractured paths."
—Persona 5 background
Kushi Mitama is the second Persona of the Strength Arcana and can only be obtained through fusion in the Velvet Room. It is the first Persona to learn Regenerate 1 and Forget Boost. When itemized using Electric Chair execution, Kushi Mitama will yield a Forget Boost skill card.
Persona 5 Royal
Kushi Mitama is instead the first Persona of the Councillor Arcana in Persona 5 Royal.
Devil Survivor 2
Like all the other Mitamas, fusion for Kusi Mitama can only be unlocked in a New Game Plus.