|This article about a/an ally/set of alternate forms in Kamen Rider Ghost.|
Musashi Damashii (ムサシ魂 Musashi Damashī, lit. "Musashi Soul") is an alternate red swordsman-based form of the ghost Riders themed after Miyamoto Musashi, a legendary Japanese swordsman and the founder of the Niten Ichi-ryū swordsmanship in Japanese martial arts. Accessed through the Musashi Ghost Eyecon, this form bears the Persona Sword Master (ペルソナソードマスター Perusona Sōdo Masutā) helmet with the Face Dual Wield (フェイスデュアルウィード Feisu Dyuaru Wīdo) faceplate. While it is mostly used by Kamen Rider Ghost, it can also be used by other Riders.
While assuming Musashi Damashii, a Kamen Rider dons the Hood of Twin Heavens (ニテンノフード Niten no Hūdo) adorned with both the Setsuna Hachimaki (セツナノハチマキ Setsuna no Hachimaki) and Five Rings' Topknot Sword (ゴリンノマゲガタナ Gorin no Mage Gatana).
As one of the 15 heroic souls, Musashi Damashii's power is also channeled through the Grateful Damashii which is accessed by Ghost via the Eyecon Driver G, appearing on Grateful's Armor Sublime as the MusaShell Breast (ムサシェルブレスト Musasheru Buresuto).  Manifesting as a body, the Musashi Ghost fights with his weapon of choice being the Gan Gun Saber Nitouryu Mode.
- "Musashi, come forth."
"Shinmen Musashi is here."
- ―Ryu Tenkuji summons Musashi[src]
In an evidently forgotten dream that Takeru had before his first death, the ghost of Musashi as well as Edison and Newton witnessed the arrival of a miniature spaceship which contained their Ghost Eyecons along with the Ore Eyecon whom exited after it arrived at a concert. Signaled by Sennin pointing to his illustration in a book of historical figures, Musashi would be first in a succession of three Damashii which were used by Kamen Rider Ghost to fight the Gamma Commandos.
War with the Gamma
The Musashi Parka Ghost was the first to be unsealed by Ghost, coming from Takeru's pendant of Miyamoto Musashi's tsuba, given to him by his father prior to his death. Ghost unsealed it during a battle against a horde of Gamma Commandos, taking Musashi Damashii and easily fighting through them all, before defeating the Katana Gamma who was leading them with Omega Slash.
Ghost briefly used Musashi Damashii against the Denki Gamma, but his dual swords acted as an easy conduit for the Gamma's electrical attacks, leaving him stunned as the Gamma escaped.
Ghost used Musashi Damashii to fight the Ono Gamma, deflecting the axes it threw, but it disappeared.
Ghost tried to use the Musashi Eyecon against an attacking Kamen Rider Specter Edison Damashii, but it was knocked out of his hand. Luckily, Akari jumped in and kept the Eyecon safe after Takeru retreated, as Specter wouldn't attack her. She later got it back to Ghost, who used Musashi Damashii's Omega Drive/Slash to defeat the Onpu Gamma.
Ghost assumes Musashi Damashii against Specter's Nobunaga Damashii after Specter interrupted his fight with the Insect Gamma, but he soon switched back to Ore Damashii, believing in his own power. Later, Ghost tried using Musashi Damashii to fight the Insect Gamma, but it dissolved into a swarm of bees and avoided his Omega Stream.
Attacked by Specter Nobunaga Damashii again, Ghost assumes Musashi Damashii to fight back, but he was knocked back to Ore Damashii by Omega Spark.
Takeru assumes Ghost Musashi Damashii when Makoto attacks him and Akari with Specter Tutankhamun Damashii. Later, it and all of Ghost and Specter's other Eyecons are sucked away by Chikara Saionji possessing the the remaining Eyecons, and are used to access the power of the Great Eye.
After the connection to the Great Eye ended, the Eyecons fell back to the ground around the Daitenku Temple; Musashi's fell in the Temple's inner garden, where Akari found and gave it to Takeru. He used Ghost Musashi Damashii briefly in the fight against Jabel. When facing one of the four Gundari Jabel had called forth, Musashi summoned himself from his Eyecon to assist Ghost, revealing here for the first time that the Parka Ghosts can act independently and speak. He and Ghost's 6 other Heroic Eyecon Parkas attached to him at once underneath his Ore Parka, letting him use an Omega Drive strong enough to destroy the Gundari.
Musashi's was one of the Eyecons reviewed by Takeru and the others shortly before the trail for the Ikkyu Eyecon appeared.
Ghost briefly assumed Musashi Damashii twice while fighting the older Sohei Gamma.
After Specter used his newly-obtained Houdini Damashii to defeat Jabel in his Gundari-empowered form, Musashi brought Takeru into his Eyecon and praised him for believing in his friends, saying that the other Heroic Spirits can be won over in similar manners.
Fighting the Gamma Superior Perfect as Toucon Boost Damashii in defense of the Gazai Gamma, Ghost adopted Toucon Musashi Damashii against the Gamma Superior Seiryuto. Igor soon left the fight to advance on Gazai, attempting to strike him down only for Ghost to take the hit, telling Igor that he would not let him hurt his Gamma friend. As Ghost prepared his Omega Drive, Igor said that this was not the venue to exhibit his true potential anyway and so left.
When the 15 Eyecons are gathered, Musashi was the one to lead the Damashiis to aid Takeru and was the one to bring the Eyecon Driver G to Takeru and unite the powers of the Eyecons, letting Takeru transform into Ghost Grateful Damashii for the first time.
Corresponding color-wise to Zyuoh Eagle, Musashi Damashii was third in a succession of three Damashii which were assumed by Ghost in his fight with the Shocker cyborg Shiomaneking in the presence of the Zyuohgers. Musashi was subsequently brought forth amongst all fifteen heroic Parka Ghosts as Ghost Grateful Damashii performed the Grateful Omega Drive kick to defeat Shiomaneking.
Musashi was defeated by Adel Blade during the disastrous engagement against Adel and his 11 remaining Gammaizers by the 15 Heroic Ghosts and Ghost Grateful Damashii, having chosen not to rely on Mugen Damashii's power alone while facing the Gammaizers. Viewing themselves as now obsolete, the heroic ghosts would enter a brief period of unresponsiveness before soon enough returning to Takeru's side, as he asserted his faith in them, against Gyro.
Acting on the advisement of Billy the Kid, Ghost Grateful Damashii summoned Musashi and Houdini to restrain the Gammaizer Magnetic Blade's blades and magnetism respectively, providing an opening for Billy the Kid to use his firepower to free Shinichiro Natsume from the Gammaizer's body.
Village of Heroes
Attacked by Dark Necrom Red and Dark Ghost, Ghost was robbed of his Eyecons which were taken as part of Argos' machination. When Takeru and his friends followed them to the Island of Eyecons, Musashi was found to be living in harmony as one of 100 reincarnated historical figure within the Village of Heroes. When Argos' Gamma forces attacked the village, Musashi was one of only four survivors who were protected by Takeru, Akari and Onari. However, while an escape from Dark Necrom Blue was covered by Kamen Rider Ex-Aid, Dark Ghost eventually caught up and Musashi was struck down and reduced back to an Eyecon which was recovered along with the others by Argos. Gathering all 100 heroic Eyecons, Argos used them as a sacrifice along with Darwin's power of evolution to convert Takeru's dead body into a vessel for the ultimate Eyecon, the Extremer Driver, which he intended to use to fulfill his ultimate agenda of converting all life on both Earth and the Gamma World into ghosts. Ultimately, however, Takeru was able to gain the strength of the 100 heroes along with his friend's spirits, allowing him to defeat Argos seemingly at the cost of his own existence only for the 100 heroes to use their power to restore his soul with the original fifteen heroes returning to his side as he came back to Earth.
When Takeru was overwhelmed by the masses of voices he was hearing through his connection to Demia, Musashi brought him into his Eyecon again, this time appearing in his human form on a sandy shoreline, where he challenged Takeru to a sword duel; he used his real-world swords while Takeru used the Gan Gun Saber in Nitouryu Mode. Musashi disarmed Takeru and told him that everything had a voice; Takeru managed to clear his mind and sift between what he was hearing, letting him catch Musashi's sword mid-swing. Now able to filter through the voices he was hearing, Musashi sent Takeru back to the real world.
The Dr. Pac-Man Incident
Musashi was first in a succession of forms assumed by Ghost in a vein attempt to engage the Hatena Bugster. Soon after, Ghost brought forth all fifteen heroic spirits with the Eyecon Driver G only for Hatena to repel even the God Omega Drive; Takeru would ultimately resort to a new power.
In early September 2018, Musashi's Parka Ghost was summoned alongside Ore, Newton and Edison via the GhostArmor wielded by Geiz, who had traveled from the year 2068 to kill Sougo Tokiwa, who became Kamen Rider Zi-O.
In 2011, the Musashi Parka Ghost was summoned alongside Ore, Newton and Edison by Geiz to rout away Another Fourze.
On December 9th 2018, the Musashi and Edison Ghosts were summoned by Geiz GhostArmor in his battle against the duo of Another Ghost, who summoned Newton and Robin Hood, and Decade Ghost, who summoned Billy the Kid and Benkei. The six Parka Ghosts engaged in a brief skirmish which soon ended as they seemingly annihilated one another.
Super Movie Wars Genesis
(Non-canon events.) The Musashi Eyecon was almost stolen by the Gamma Superior Gamma A, but he was stopped by Ghost, Specter, Dead Heat Drive, and Mach. Musashi was later one of the Parka Ghosts to merge into the Toucon Boost (Tousan) Eyecon, letting Ghost help Drive destroy the Renaissance Gamma.
Musashi is among the historical figures who are featured in Stories of the World's Greatest People, the book passed down to Takeru Tenkuji by Ryu Tenkuji. He is acknowledged under The Number 1 Swordsman in the World: Musashi Miyamoto (世界一の剣豪 宮本武蔵 Sekai-ichi no Kengō: Miyamoto Musashi).
- Kamen Rider Ghost (Special Preceding Video, Ghost Episodes 1-3, 6-8, Super Movie Wars Genesis, Ghost 10, 11, Ikkyu Eyecon Contention!, Ikkyu Intimacy!, Zyuohger Episode 7, Ghost 38, Heisei Generations: Dr. Pac-Man vs. Ex-Aid & Ghost with Legend Rider)
- Toucon Boost (Ghost Episode 20, The 100 Eyecons and Ghost's Fateful Moment)
- Grateful Damashii (Ghost Episode 23, Zyuohger Episode 7, Ghost 25, 34, 38, 40, Heisei Generations: Dr. Pac-Man vs. Ex-Aid & Ghost with Legend Rider, Heisei Generations FINAL: Build & Ex-Aid with Legend Riders)
- Mugen (Ghost Change)
- Kamen Rider Specter (Kamen Rider Battle: Ganbarizing)
- Deep Specter (Ghost Change)
- Kamen Rider Necrom (Kamen Rider Battle: Ganbarizing)
- Kamen Rider Dark Ghost (Ghost Change)
- Omega Drive (Musashi) (オメガドライブ ムサシ Omega Doraibu (Musashi)): When assuming Toucon Musashi Damashii, Ghost creates a set of energy blades on the Gan Gun Saber in Blade Mode and the Sunglasseslasher in Sword Mode and then slashes the enemy. In episode 20, Ghost attempted to use this finisher on Gamma Superior Seiryuto but he disappeared before Ghost could finish him.
- Omega Formation (Musashi and Edison): Ghost performs a flying kick, the Musashi Parka Ghost performs a slash attack with the Gan Gun Saber in Nitouryu Mode and the Edison Parka Ghost performs a shooting attack with the Gan Gun Saber in Gun Mode. In episode 34, Ghost attempted to use this finisher on Denki Gamma and Book Gamma but the Grimm brothers couldn't cooperate and their emblem disappeared.
- Omega Slash (オメガスラッシュ Omega Surasshu): In Nitouryu Mode, Ghost batters the opponent with his weapon's blades as they charge up energy before he presses the trigger on its handle when he's in position to cut down the opponent to make the charge be expelled upon the last hit.
Behind the scenes
As with the rest of the 15 heroic Parka Ghosts, Musashi is voiced by Tomokazu Seki (関 智一 Seki Tomokazu). His suit actor as a full body ghost is unknown. His human form in Kamen Rider Ghost the Movie: The 100 Eyecons and Ghost’s Fateful Moment and episode 46 of the series is portrayed by Mitsuru Karahashi (唐橋 充 Karahashi Mitsuru), who previously portrayed Naoya Kaido the Snake Orphnoch in Kamen Rider 555.