Kaolinite is Professor Tomoe's devoted assistant and has a pretty obvious crush on him. She first showed up in Act 24 of the manga and Episode 90 of the anime, though fans know her as Kaori Night in the manga and Kaorinite in the English dub.
The two versions of her character differ pretty significantly, especially when it comes to Hotaru. In the anime, Kaori's constantly mocking and provoking the girl, whereas the manga portrays her as actually caring about her—though Hotaru doesn't appreciate either version, resenting what she sees as Kaolinite overstepping her place in the family.
She's got some solid abilities in her arsenal: levitation, teleportation, limited shape-shifting, and the neat trick of weaponizing her own hair like Mistress 9 does.
In the anime, Kaolinite's the first Death Buster to actively hunt down people with pure heart crystals, deploying the bio-engineered Daimons she helped design. She's after the three Talismans (which turn out to belong to Uranus, Neptune, and Pluto, though she doesn't know that). She manages to target Mars, Mercury, and Jupiter before going after Sailor Moon directly in episode 102. The Senshi band together to stop her, and Uranus takes her down with World Shaking, trapping her in a glass pillar that sends her plummeting from Tokyo Tower. But Professor Tomoe brings her back, and by episode 113 she's reappeared as Hotaru's guardian. Bitter about being replaced by the Witches 5, she eventually steals Chibi Moon's pure heart crystal and delivers it to Hotaru—triggering her awakening as Mistress 9. Kaolinite's final moments are spent getting thrown into an electrified wall by the very entity she helped create.
The manga version has a completely different origin story. During a storm, as Tomoe was trying to rebuild his daughter's body, Kaolinite was struck by lightning—and when she stood back up, her eyes were glowing. She earned the title "Magus Kaolinite," a rank the Witches 5 aspire to reach, which comes with access to the Tau Star System's crystal. In this version, the Witches 5 answer to her, not Tomoe, and she treats them as servants. She's apparently harboring her own ambitions too, wanting to replace Mistress 9 as Pharaoh 90's partner—something Mistress 9 finds darkly amusing. When Mistress 9 eventually wakes up and orders her to take out the Sailor Senshi, Kaolinite manages to subdue the Guardian Senshi before Uranus, Neptune, and Pluto bail them out. The final confrontation happens in Infinity Academy's president's office, where Kaolinite transforms into a Daimon and gets taken down by Super Sailor Moon's Rainbow Moon Heartache.
Content compiled by AnimeList.moe from publicly available sources.
