Mimete is the second of the Witches 5, best known for being kind of a mess compared to her sisters. She first shows up fighting the Sailor Senshi in episode 112 of the anime, and she's named after the mineral mimetite.
In the anime, she takes over collecting pure hearts after Eudial dies. Problem is, Mimete's easily distracted and would rather flirt with attractive celebrities than actually do her job—she's definitely the least organized of the Witches 5. Her Daimons have this gross ability to literally suck pure heart crystals right out of people's mouths. To take them down, the Senshi need the Holy Grail. Mimete's signature move is "Charm Buster" (called "Stage Fright" in the English dub). After botching her heart collection duties repeatedly, she decides to use one of Eudial's old machines—the Witches Electric Warp—to beef herself up. Right as she's about to unleash her powered-up form, Tellu cuts the power, and Mimete gets trapped inside forever. That's the end of her.
The manga version is different. Here she goes by Mimi Hanyu and runs the Acting Class in Infinity Academy's Talent Division. She's the lowest ranked of the Witches 5 at Level 40. She uses the same "Charm Buster" attack and disguises herself as a pop idol, throwing a concert for academy students to steal their Hostes. Sailor Venus catches on and shows up undercover, and when the rest of the Senshi arrive, Mimete tries calling in Kaolinite to activate Daimon eggs implanted in the crowd—but it doesn't work. Sailor Uranus kills her.
Content compiled by AnimeList.moe from publicly available sources.