Mizuki Rashojin (
1000 years before the series begins, she was an infant who was thrown into the sea due to a country famine. Since she was abandoned with hatred and was filled with an intense fear before her death, her spirit inadvertently made a pact with Ambrosia. She miraculously survived this event and washed ashore the Shimokita Peninsula to a new family. The villagers there named her Mizuki (which means "seeing") since she seemed to possess mystical abilities.
Thirteen years later, the village made a sacrifice and it formally contracts Ambrosia. Mizuki then became an evil entity, Rashojin Mizuki. Since then, she has terrorized the land with various disasters around the area. She evolved to a state where she could host another body and keep herself intact using its energy. 300 years later, she reaches her mental limit and hibernates near a shrine to recover her strength. A century later, she found a shrine priestess, Bizuki, to be a suitable host. From then on, Mizuki fed off Bizuki's heightened spiritual senses. She was sealed into a mountain hundreds of years later by several puppets and monks. Though she appeared to be dormant, she was actually sleeping and gathering her energies.
Thirty years before Samurai Shodown II begins, she has a brief encounter with Nicotine Caffeine and Kuroko. She was awakened by Amakusa's powers and soon invoked Ambrosia's mortal resurrection. To aid her work, she also hired a band of henchmen which includes Earthquake, Genan, and Genjuro (though he eventually betrays her due to lack of interest). Haohmaru, whom had successfully survived the trip to Hell, stop her plans from succeeding. Upon her defeat, Mizuki and Ambrosia were sealed in the Makai (demon world).
In the RPG, Mizuki was a rural Japanese child abandoned by her family due to severe poverty. Bitter with hatred and consumed with revenge, she made a pact with the evil god Ambrosia roughly a thousand years before the series begins, turning herself into a demon. Since this acquisition of demonic power, she proceeds to cause worldwide disasters and calamities around the globe. However, roughly 800 years after her pact, she was challenged by a priestess named Bizuki. Despite her best efforts to purify the entity, Bizuki was possessed by Mizuki and sent into hibernation. When the party faces and defeats Mizuki, her body disintegrates into a skeletal form. She summons Ambrosia's grotesque body to finish off her adversaries, and is defeated.
The King of Fighters
As a result of being defeated, her soul is absorbed by Verse, and is released once the latter is defeated. As with many souls inside Verse that was released, Mizuki is suspected to have been revived.
Mizuki is a vengeful spirit that hates humanity. She preys on the weak and claims all of her acts of cruelty in Ambrosia's name. She thinks very highly of herself, often laughing at her enemies for attempting to even stop her.
- Claws - Mizuki's nails have been transformed into sharp claws.
- Translocation - Mizuki can dash herself forward at incredible speeds.
- Teleportation - Mizuki can warp through the ground, appearing in another location moments later.
- Transformation Magic - Mizuki can command her demon companion to spit a magical ball of energy. When it hits her opponent, it changes them into a defenseless animal.
- Hell Drop - Mizuki can summon a demon to drag them into a dimensional portal; they'll smash from above moments later.
- Boomerang Projectile - Mizuki can launch a projectile that will fly back towards her after a short distance, hitting her enemies that attempt to jump over it.
- Levitation - Mizuki can grab her opponents and levitate them to a high height, dropping them afterward for damage.
- Seals - Mizuki has an array of seals to her disposal. She can reverse controller motions, prevent her enemy's powers for a time, and prevent her opponent from attacking for a time.
- Multiple Attacks - Mizuki can slap her opponents multiple times at once.
- Energy Attacks - Mizuki can put energy in her weapon.
Mizuki has a wide arsenal of attacks to choose from. In some ways, she is similar to Nicotine in that they can both shoot upper and lower angled projectiles and also reverse their foes movements. Like her predecessor, Amakusa, she also possesses the ability of teleportation and a multi-hitting slap attack. She can also command a demon pet to disabling her opponents attacks for a time. Her desperation attack is a unique projectile that will boomerang back to her if her opponent jumps over it. She is also quick on her feet, easily able to close distances between her foe in quick dashes with little trouble. She loses some of these powers with her playable appearance in Samurai Shodown V Special; her special moves are also made a shorter range to balance herself with other characters. She gains more access to different sealing abilities but can only execute these spells at a close range.
In the game he premiered, Maju is by Mizuki's side. Like Poppy, he can be commanded by the player to bash into and maul opponents. He can also fire an electric ball that can turn foes into animals -the most common result being a pig- rendering the player's opponents unable to input special commands and defenseless against Mizuki for one attack before reverting to normal (alternatively, transformed opponents can also wait a few seconds before the effects wear off). Appearance-wise, he is an alternative color palette of Poppy when he is idle, but morphs into a giant demonic creature when he is commanded, making him able to catch most opponents who try to jump over his attacks. Though instances are rare, he can be injured and his attacks can be interrupted. Players must also keep an eye on which direction he is facing whilst commanded, as he may attack in the opposite direction of their opponent. In Samurai Shodown V Special, he is summoned in his demonic form by Mizuki via teleportation and is not visible by the player until then.
- The Final Battle - Samurai Shodown II
- Evil Deity - Samurai Shodown II
- Lunatic - Samurai Shodown II
- Great Evil Spirit - Shinsetsu Samurai Spirits Bushidō Retsuden
- Dark Cloud - Shinsetsu Samurai Spirits Bushidō Retsuden
- Ma no Ongaku - Nakoruru ADV
- Harumi Ikoma - Samurai Shodown II, Samurai Shodown VI (re-dub voice)
- Rica Matsumoto - Shinsetsu Samurai Spirits: Bushidou Retsuden
- Miki Tsuchiya - Nakoruru ~Ano hito kara no okurimono~
- Shizuka Ito - Samurai Shodown V Special
- Tsumugi Ōsawa - Samurai Shodown VI
- Michie Tomizawa - Samurai Shodown II Dengeki drama CD
- Samurai Shodown II
- Shinsetsu Samurai Spirits: Bushidou Retsuden - as the second antagonist
- Samurai Shodown V Special
- Samurai Shodown V Perfect
- Samurai Shodown VI
- Nakoruru: Ano Hito kara no Okurimono
- Samurai Shodown Online
- SNK High School Collention
- Kingdom Story
- Kimi wa Hero
- Samurai Shodown: Oborozuki Densetsu
- Samurai Shodown Tenkadaiichi Kenkakuden
- Samurai Shodown IV - in Kyoshiro's ending, her laugh is also shown in-text before the credits
- The King of Fighters XIV - as Verse's win quote against Nakoruru
- KOF: Maximum Impact 2 - bonus stage cameo
- SNK vs Capcom: Match of the Millenium - during Akari's super
- Maid by Iroha
- Days of Memories (ninth title)
- Samurai Spirits 2: Asura-Zanmaden (OVA) - in Shiki's visions
- Mizuki's unique laugh is written as "ラキキキキ..." (Rakikikiki...) or "RGKKKKKK". Players can see a variation of it as an easter egg before Samurai Shodown IV's credits ("ラキ, ラキ, ラキキ...."), most likely hinting at her eventual awakening. This unique laugh is later used by Verse in The King of Fighters XIV as its special win quote against Nakoruru.
- When asked "The path of the sword is?", Mizuki's response is "The path of destruction." 
- In her first appearance, she speaks mainly in Siddhaṃ. One of the mantras mentions a Dakini.