Genkishi was an A-rank Millefiore subordinate known as Byakuran's right-hand man and the strongest soldier before the appearance of the Six Funeral Wreaths. This strength, coupled with his powerful illusions, earned him the nickname The Phantom Knight, leading even other Millefiore Captains, such as Gamma, to fear him. He was fiercely loyal to Byakuran, referring to him as a God and, as such, blindly followed all his orders, even going as far as betraying his former family on Byakuran's order. The only time he showed hesitation was when Yuni was around or when he was reminded of her. Though mostly calm while fighting, Genkishi lost all control whenever he used his Ossa Impressione Hell Ring and began ranting. Tsunayoshi Sawada even commented that his stoic self was more fearsome, despite having less power.
Before joining the Mafia, Genkishi was a swordsman unfortunate enough to receive an incurable disease while travelling. While in treatment, he was visited by Byakuran, who cured him using his knowledge gathered from his trips into other parallel worlds. In response, Genkishi came to know him as a god. Genkishi later joined the Giglio Nero Famiglia and acted as a spy for Byakuran during the war against the Gesso Famiglia. A ceasefire was agreed if Genkishi could defeat a powerful swordsman for the Gesso. However, Genkishi used illusions to fake his defeat so that he could kill the remaining Giglio Nero and steal their Mare Rings when their guards were down. However, their leader Yuni saw through this and held him back; thus, in order to stop further bloodshed, Yuni agreed to meet Byakuran. As a result, Byakuran drugged Yuni to dull her heart and take away her power of speech, also forcing her to agree to the joining of the Gesso and the Giglio Nero.
During the war between the Millefiore and Vongola, Genkishi was sent to Namimori in order to protect Shoichi Irie at his Melone Base. During the Vongola's invasion of the base Genkishi was positioned to intercept Lal Mirch and Takeshi Yamamoto, who he swiftly defeated. However before he could kill them he was interrupted by Kyoya Hibari. Genkishi came inches from killing him in battle but Hibari was at that moment switched with his past self and joined with the rest of the Vongola. After being separated from them, Genkishi fought Tsunayoshi Sawada and unleashed the power of his Hell Ring. However he held back, as Tsuna's eyes reminded him of Yuni's, and escaped after his defeat.
During Choice, Genkishi (disguised as Torikabuto's subordinate, Saru) was chosen as the second Mist member of the Millefiore side.
After the Vongola deployed flame decoys the Millefiore decided to destroy each one in order to find the real target. Genkishi then encountered Yamamoto and, after Genkishi revealed his true identity, the two fought for a second time. However even after using his Hell Ring, Genkishi was defeated by Yamamoto's Cambio Forma, Ugetsu Asari's Four Irregular Swords. Kikyo (on orders from Byakuran) then released a number of Bellflowers into Genkishi's Armatura that began killing him from within. Genkishi then died, still adamant that Byakuran would save him.
Weapons and Abilities
- Mystic Arte: Four Sword: Known as the Millfiore's strongest swordsman, Genkishi can use four Swords at once, holding two in his hands and two with his feet.
- Fake Mist Mare Ring: Worn by Genkishi when he was thought to be one of the Six Funeral Wreaths, but the ring only had a stone of Rank-A quality.
- Spectral Sea Slugs: A large number of slugs that create Illusions altering the landscape around opponents. They can move independently or as a group towards a target and explode on impact while remaining hidden. The only method demonstrated to avoid this attack is to use Dying Will Flames to detect a change in vibrations.
- Ossa Impressione Hell Ring: Using this Hell Ring Genkishi can summon the Weaponry of War (Armamento da Guerra), consisting of the Spettrale Spada and Nebbia Numero Due. However when used too much, the Ring will take over the users mind who will then take the form of a skeletal Knight. Illusions of the enemies loved ones can then be expelled from the Knight's mouth who can then be forced to follow the user's will. According to Genkishi the Illusions are tied to the lives of their real counterparts, though this was never confirmed.
- Spettrale Spada (Spectral Sword): The illusion sword can create multiple copies of itself as well as mist flames, to be used as countless projectiles.
- Nebbia Numero Due (Mist Number Two): The Nebbia Numero Due's technical specifications include solidness for use in close-combat, but is also light-weight and easy to move around.
- In Japanese, "Gen" means "Illusion" or "phantom" and "kishi" means "knight", thus making him "Phantom Knight".
- Genkishi participates in Choice under the name "Saru", which, in Japanese, translates to "monkey".
- In a recent popularity poll, Genkishi ranked 16th.